CellexalVR can calculate which genes vary the most in expression based on a grouping with two groups. To do this: create a selection with two groups, confirm your selection and press the "Calculate differentially expressed genes" button on the menu. This will open up a new menu with two buttons. You can choose to get the top 20 genes based on difference in mean expression value between your two groups, or let CellexalVR perform a t-test to determine the top 20 genes. This may take a long time depending on the size of your selection and data. The top 20 genes are always the top 10 genes in each end of the spectrum i.e. the top 10 genes that are more expressed in group 1 and less in group 2, and the top 10 that are less expressed in group 1 and more in group 2. Once you have chosen your method of determining the genes, buttons will appear with gene names and values. The values are the difference in either mean expression or t-value, depending on which method you chose. Clicking any of the buttons with gene names will color all graphs by that gene.