KRAS and metastatic colorectal cancer: The variant allele of LCS6 polymorphism (rs61764370 T > G) in the binding site of let-7 to KRAS 3’-UTR was reported to be associated with reduced OS and progression-free survival (PFS) in metastatic colorectal cancer (mCRC) [111], and nonresponse to anti-EGFR-based treatment in KRAS and BRAF wild-type mCRC patients [112].