In our recent publication , we have explored at the molecular level the consequences of reovirus administration to patients with KRAS mutated colorectal cancer (CRC). This was the first reported study where transcriptome assay was performed on KRAS mutated CRC patients receiving reovirus (pelareorep) therapy. Using peripheral mononuclear cells as a tumor surrogate, we have identified several hundred genes that were significantly altered in a transcriptome assay of patients receiving pelareorep serving as their own controls (pre and post reovirus administration) and compared to untreated controls . We focused primarily on 884 immune related genes and published the data for genes with significance probability of 0.001 (1 in thousand for a perfect random occurrence). Samples were collected at 48 hours, day 8 and day 15 post reovirus administration and compared for dynamic gene expression alterations over time. Using PBMC we also performed flow cytometry, cytokine ELISA, immunohistochemistry, and determination of the expression level of CRC specific microRNA miR-29a-3p. Our data supports the therapeutic competence of reovirus and identifies the four major ways by which it exerts its antitumor effects.