Many of the false-positive mutation calls in the Pre-OP samples were found to be a mutation leading to the KRAS G12V variant, and it could therefore potentially be explained by a sub-clonal variant that was not identified in the tumor sample or a germline signal of clonal hematopoiesis of indeterminate potential (CHIP) that was not identified in the buffycoat samples. This evidence concerns the gene KRAS and neoplasm.