Because aggressive MSI‐H CRC may result from escaping the immune surveillance of cytotoxic lymphocytes and NK cell is a type of cytotoxic immune cells, which target cancer cells in an antigen‐independent manner [24], we use NK‐92MI cells as a model cell line to explore the roles of CT45A1 in the cancer susceptibility to cytotoxic killing. This evidence concerns the gene CT45A1 and cancer.