diff --git a/NAMESPACE b/NAMESPACE
index ed26bd9..2c6a547 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -40,6 +40,7 @@ export(trust4)
 export(trust4_gene_names)
 export(trust4_imgt_annot)
 export(uninstall_appmamba)
+export(varscan)
 importFrom(R6,R6Class)
 importFrom(rlang,":=")
 importFrom(rlang,.data)
diff --git a/R/cmd-varscan.R b/R/cmd-varscan.R
new file mode 100644
index 0000000..1728d3b
--- /dev/null
+++ b/R/cmd-varscan.R
@@ -0,0 +1,45 @@
+#' VarScan is a platform-independent software tool 
+#' developed at the Genome Institute at Washington University to detect variants in NGS data.
+#'
+#' @param subcmd Sub-Command of varscan. Details see: `r rd_help("varscan")`.
+#' @param ... `r rd_dots("varscan")`.
+#' @param varscan `r rd_cmd("varscan")`.
+#' @seealso
+#' - <https://varscan.sourceforge.net/>
+#'
+#' `r rd_seealso()`
+#' @inherit exec return
+#' @family command
+#' @export
+varscan <- make_command(
+  "varscan",
+  function(
+    subcmd = NULL,
+    ...,
+    varscan = NULL
+    ) {
+    assert_string(subcmd, allow_empty = FALSE, allow_null = TRUE)
+    assert_string(varscan, allow_empty = FALSE, allow_null = TRUE)
+    Varscan$new(
+      cmd = varscan,
+      ...,
+      subcmd = subcmd
+    )
+  }
+)
+
+Varscan <- R6Class(
+  "Varscan",
+  inherit = Command,
+  private = list(
+    alias = function() "varscan",
+    setup_help_params = function() "help",
+    combine_params = function(subcmd) {
+      if (private$help) {
+        c(super$combine_params(), subcmd)
+      } else {
+        c(subcmd, super$combine_params())
+      }
+    }
+  )
+)
\ No newline at end of file
diff --git a/man/allele_counter.Rd b/man/allele_counter.Rd
index af89e9b..e5a425d 100644
--- a/man/allele_counter.Rd
+++ b/man/allele_counter.Rd
@@ -55,6 +55,7 @@ Other \code{commands}:
 \code{\link{python}()},
 \code{\link{samtools}()},
 \code{\link{seqkit}()},
-\code{\link{trust4}()}
+\code{\link{trust4}()},
+\code{\link{varscan}()}
 }
 \concept{command}
diff --git a/man/cellranger.Rd b/man/cellranger.Rd
index c6132c1..bfe9836 100644
--- a/man/cellranger.Rd
+++ b/man/cellranger.Rd
@@ -59,6 +59,7 @@ Other \code{commands}:
 \code{\link{python}()},
 \code{\link{samtools}()},
 \code{\link{seqkit}()},
-\code{\link{trust4}()}
+\code{\link{trust4}()},
+\code{\link{varscan}()}
 }
 \concept{command}
diff --git a/man/conda.Rd b/man/conda.Rd
index 876b7ed..7dfc20b 100644
--- a/man/conda.Rd
+++ b/man/conda.Rd
@@ -40,6 +40,7 @@ Other \code{commands}:
 \code{\link{python}()},
 \code{\link{samtools}()},
 \code{\link{seqkit}()},
-\code{\link{trust4}()}
+\code{\link{trust4}()},
+\code{\link{varscan}()}
 }
 \concept{command}
diff --git a/man/exec.Rd b/man/exec.Rd
index 64e7f40..3b9ff68 100644
--- a/man/exec.Rd
+++ b/man/exec.Rd
@@ -34,6 +34,7 @@ Invoke a System Command
 \item \code{\link[=samtools]{samtools()}}
 \item \code{\link[=seqkit]{seqkit()}}
 \item \code{\link[=trust4]{trust4()}}
+\item \code{\link[=varscan]{varscan()}}
 }
 }
 
diff --git a/man/fastp.Rd b/man/fastp.Rd
index 1be6075..a6c3156 100644
--- a/man/fastp.Rd
+++ b/man/fastp.Rd
@@ -44,6 +44,7 @@ Other \code{commands}:
 \code{\link{python}()},
 \code{\link{samtools}()},
 \code{\link{seqkit}()},
-\code{\link{trust4}()}
+\code{\link{trust4}()},
+\code{\link{varscan}()}
 }
 \concept{command}
diff --git a/man/fastq_pair.Rd b/man/fastq_pair.Rd
index f432d1b..52596ae 100644
--- a/man/fastq_pair.Rd
+++ b/man/fastq_pair.Rd
@@ -65,6 +65,7 @@ Other \code{commands}:
 \code{\link{python}()},
 \code{\link{samtools}()},
 \code{\link{seqkit}()},
-\code{\link{trust4}()}
+\code{\link{trust4}()},
+\code{\link{varscan}()}
 }
 \concept{command}
diff --git a/man/gistic2.Rd b/man/gistic2.Rd
index 487a27e..58f0f78 100644
--- a/man/gistic2.Rd
+++ b/man/gistic2.Rd
@@ -62,6 +62,7 @@ Other \code{commands}:
 \code{\link{python}()},
 \code{\link{samtools}()},
 \code{\link{seqkit}()},
-\code{\link{trust4}()}
+\code{\link{trust4}()},
+\code{\link{varscan}()}
 }
 \concept{command}
diff --git a/man/kraken2.Rd b/man/kraken2.Rd
index 37c439a..874acd5 100644
--- a/man/kraken2.Rd
+++ b/man/kraken2.Rd
@@ -68,6 +68,7 @@ Other \code{commands}:
 \code{\link{python}()},
 \code{\link{samtools}()},
 \code{\link{seqkit}()},
-\code{\link{trust4}()}
+\code{\link{trust4}()},
+\code{\link{varscan}()}
 }
 \concept{command}
diff --git a/man/kraken_tools.Rd b/man/kraken_tools.Rd
index cf873d6..853eb51 100644
--- a/man/kraken_tools.Rd
+++ b/man/kraken_tools.Rd
@@ -44,6 +44,7 @@ Other \code{commands}:
 \code{\link{python}()},
 \code{\link{samtools}()},
 \code{\link{seqkit}()},
-\code{\link{trust4}()}
+\code{\link{trust4}()},
+\code{\link{varscan}()}
 }
 \concept{command}
diff --git a/man/perl.Rd b/man/perl.Rd
index 89eed70..0cecea3 100644
--- a/man/perl.Rd
+++ b/man/perl.Rd
@@ -41,6 +41,7 @@ Other \code{commands}:
 \code{\link{python}()},
 \code{\link{samtools}()},
 \code{\link{seqkit}()},
-\code{\link{trust4}()}
+\code{\link{trust4}()},
+\code{\link{varscan}()}
 }
 \concept{command}
diff --git a/man/pyscenic.Rd b/man/pyscenic.Rd
index db6b9dd..d955cf3 100644
--- a/man/pyscenic.Rd
+++ b/man/pyscenic.Rd
@@ -41,6 +41,7 @@ Other \code{commands}:
 \code{\link{python}()},
 \code{\link{samtools}()},
 \code{\link{seqkit}()},
-\code{\link{trust4}()}
+\code{\link{trust4}()},
+\code{\link{varscan}()}
 }
 \concept{command}
diff --git a/man/python.Rd b/man/python.Rd
index 7b5c513..3f4e2bc 100644
--- a/man/python.Rd
+++ b/man/python.Rd
@@ -41,6 +41,7 @@ Other \code{commands}:
 \code{\link{pyscenic}()},
 \code{\link{samtools}()},
 \code{\link{seqkit}()},
-\code{\link{trust4}()}
+\code{\link{trust4}()},
+\code{\link{varscan}()}
 }
 \concept{command}
diff --git a/man/samtools.Rd b/man/samtools.Rd
index ed59740..70d1227 100644
--- a/man/samtools.Rd
+++ b/man/samtools.Rd
@@ -43,6 +43,7 @@ Other \code{commands}:
 \code{\link{pyscenic}()},
 \code{\link{python}()},
 \code{\link{seqkit}()},
-\code{\link{trust4}()}
+\code{\link{trust4}()},
+\code{\link{varscan}()}
 }
 \concept{command}
diff --git a/man/seqkit.Rd b/man/seqkit.Rd
index 6922f84..83a988c 100644
--- a/man/seqkit.Rd
+++ b/man/seqkit.Rd
@@ -41,6 +41,7 @@ Other \code{commands}:
 \code{\link{pyscenic}()},
 \code{\link{python}()},
 \code{\link{samtools}()},
-\code{\link{trust4}()}
+\code{\link{trust4}()},
+\code{\link{varscan}()}
 }
 \concept{command}
diff --git a/man/trust4.Rd b/man/trust4.Rd
index ae887a7..bd0cdd2 100644
--- a/man/trust4.Rd
+++ b/man/trust4.Rd
@@ -96,6 +96,7 @@ Other \code{commands}:
 \code{\link{pyscenic}()},
 \code{\link{python}()},
 \code{\link{samtools}()},
-\code{\link{seqkit}()}
+\code{\link{seqkit}()},
+\code{\link{varscan}()}
 }
 \concept{command}
diff --git a/man/varscan.Rd b/man/varscan.Rd
new file mode 100644
index 0000000..791ea29
--- /dev/null
+++ b/man/varscan.Rd
@@ -0,0 +1,49 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/cmd-varscan.R
+\name{varscan}
+\alias{varscan}
+\title{VarScan is a platform-independent software tool
+developed at the Genome Institute at Washington University to detect variants in NGS data.}
+\usage{
+varscan(subcmd = NULL, ..., varscan = NULL)
+}
+\arguments{
+\item{subcmd}{Sub-Command of varscan. Details see: \code{cmd_help(varscan())}.}
+
+\item{...}{<\link[rlang:dyn-dots]{dynamic dots}> Additional arguments passed to \code{varscan} command. Empty arguments are automatically trimmed. If a single argument, such as a file path, contains spaces, it must be quoted, for example using \code{\link[=shQuote]{shQuote()}}. Details see: \code{cmd_help(varscan())}.}
+
+\item{varscan}{A string of path to \code{varscan} command.}
+}
+\value{
+A \code{command} object.
+}
+\description{
+VarScan is a platform-independent software tool
+developed at the Genome Institute at Washington University to detect variants in NGS data.
+}
+\seealso{
+\itemize{
+\item \url{https://varscan.sourceforge.net/}
+\item \code{\link[=cmd_wd]{cmd_wd()}}/\code{\link[=cmd_envvar]{cmd_envvar()}}/\code{\link[=cmd_envpath]{cmd_envpath()}}/\code{\link[=cmd_condaenv]{cmd_condaenv()}}
+\item \code{\link[=cmd_on_start]{cmd_on_start()}}/\code{\link[=cmd_on_exit]{cmd_on_exit()}}
+\item \code{\link[=cmd_on_succeed]{cmd_on_succeed()}}/\code{\link[=cmd_on_fail]{cmd_on_fail()}}
+\item \code{\link[=cmd_parallel]{cmd_parallel()}}
+}
+
+Other \code{commands}:
+\code{\link{allele_counter}()},
+\code{\link{cellranger}()},
+\code{\link{conda}()},
+\code{\link{fastp}()},
+\code{\link{fastq_pair}()},
+\code{\link{gistic2}()},
+\code{\link{kraken2}()},
+\code{\link{kraken_tools}()},
+\code{\link{perl}()},
+\code{\link{pyscenic}()},
+\code{\link{python}()},
+\code{\link{samtools}()},
+\code{\link{seqkit}()},
+\code{\link{trust4}()}
+}
+\concept{command}
diff --git a/tests/testthat/test-exec.R b/tests/testthat/test-exec.R
index acda33e..96557e5 100644
--- a/tests/testthat/test-exec.R
+++ b/tests/testthat/test-exec.R
@@ -66,3 +66,29 @@ testthat::test_that("`pipe()` method works well", {
         cmd_run()
     testthat::expect_identical(read_lines(file), read_lines(file2))
 })
+
+testthat::test_that("`varscan()` works as expected", {
+  testthat::skip_if_not(nzchar(Sys.which("varscan")))
+  varscan() |> cmd_help()
+})
+
+testthat::test_that("`fastp()` works as expected", {
+  testthat::skip_if_not(nzchar(Sys.which("fastp")))
+  fastp() |> cmd_help()
+})
+
+
+testthat::test_that("`snpeff()` works as expected", {
+  testthat::skip_if_not(nzchar(Sys.which("snpeff")))
+  snpeff() |> cmd_help()
+})
+
+testthat::test_that("`bcftools()` works as expected", {
+  testthat::skip_if_not(nzchar(Sys.which("bcftools")))
+  bcftools() |> cmd_help()
+})
+
+testthat::test_that("`bowtie2()` works as expected", {
+  testthat::skip_if_not(nzchar(Sys.which("bowtie2")))
+  bowtie2() |> cmd_help()
+})
\ No newline at end of file