SMAD4 and cancer: The specific core GEN of old men showed that STMN1 and LRRFIP2 are inhibited by mir-210 and mir-214, respectively, and DNA methylation of SMAD4 and LEF1, which may lead to dysregulation of the MAPK signaling and Wnt signaling pathways as well as deregulation of the cell cycle and apoptosis, thus resulting in cancer.