TCF4 and colorectal carcinoma: Meanwhile, recent studies have showed that miR‐135b can be transcriptionally activated by β‐catenin/TCF4, which leads to the up‐regulation of miR‐135b in CRC.45, 75 Unlike miR‐135, miR‐21 can increase β‐catenin nuclear translocation and promote tumorigenesis in CRC.76 miR‐155 is also a Wnt/β‐catenin stimulator by targeting HMGB1 and indirectly increasing Wnt/β‐catenin expression.77, 78 The RAS gene family, such as NRAS, HRAS and KRAS, and KRAS has been frequently mutated in CRCs.