PVR and cancer: Furthermore, PVR is overexpressed in several types of cancers, including serous ovarian cancer, colorectal carcinoma, hepatocellular carcinoma, lung adenocarcinoma, esophageal small cell carcinoma, and cholangiocarcinoma [5,6,7,8,9,10], and highly expressed in bone marrow cells in multiple myeloma (MM) [11].