LIG4 and colorectal carcinoma: A frameshift mutation in XRCC4, a member of the DNA ligase 4 complex involved in the last step of NHEJ, was found in a CRC patient with familial CRC history, which, together with the lack of XRCC4 variant carriers among population controls, led the authors to propose XRCC4 as a candidate gene for CRC predisposition [13].