SMAD4 and colorectal carcinoma: Gene expression analysis of SMAD4, TP53, and β-catenin has found nuclear β-catenin overexpression in the 84% of the CRC showing SMAD4-downregulation and/or TP53 deficient, suggesting that the SMAD4 and TP53 activities control the effect of BMP signaling on the WNT pathway [118].