SMAD4 and colorectal carcinoma: Although the genetic causes of FCCTX are still unknown, several studies identified some CRC predisposing genes including BRCA2, SEMA4A, APC, BMPR1A, NTS, CDH18, RPS20, GREM1, BCR, KIF24, GALNT12, ZNF367, HABP4, GABBR2, TP53, SMAD4, and BMP4 (11–13, 22–24).