The finding that Wortmannin, a member of the DNA-PK family which inhibits PIKK, and is a radiosensitiser in preclinical models, [54] led to the investigation of other DNA-PK inhibitors as potential targets such as Nu7441, a small molecule DNA-PK inhibitor found to sensitise HeLa cells to ionising radiation and etoposide [55, 56]in colon cancer. This evidence concerns the gene PRKDC and malignant colon neoplasm.