SMAD4 and cancer: Tissue microdissection and next-generation sequencing were performed using a 26 gene panel (<i>AKT1, ALK, APC, BRAF, CDH1, CTNNB1, EGFR, ERBB2, FBXW7, FGFR2, FOXL2, GNAQ, GNAS, KIT, KRAS, MAP2K1, MET, MSH6, NRAS, PDGFRA, PIK3CA, PTEN, SMAD4, SRC, STK11, TP53</i>) of cancer-related genes.