SMAD4 and cancer: In particular, the entire gene-panel targets 87 hotspot regions for the following 22 genes: RTKs (ALK, EGFR, ERBB2, ERBB4, FGFR1, FGFR2, FGFR3, MET, DDR2); RTK signaling genes (KRAS, PIK3CA, BRAF, AKT1, PTEN, NRAS, MAP2K1, STK11); and other well known cancer-related genes (NOTCH1, CTNNB1, SMAD4, FBXW7, TP53).