@@ -94,6 +94,13 @@ gene_plot <- function(dds,

     res_enrich <- gtl$res_enrich

     annotation_obj <- gtl$annotation_obj

   }

+  

+  if (!intgroup %in% colnames(colData(dds))) {

+    stop("`intgroup` not found in the colData slot of the dds object",

+         "\nPlease specify one of the following: \n",

+         paste0(colnames(colData(dds)), collapse = ", ")

+         )

+  }

   df <- get_expression_values(

     dds = dds,