SMAD4 and cancer: This list includes well-known oncogenes, CTNNB1, ERBB2, ERBB3, KRAS, PIK3CA, BRAF, and NFE2L2, tumor suppressors, TP53, ARID2, STK11, CDKN2A, SMAD4, SMARCA4, ARID1A, APC, NF1, and MAP2K4, and less well-established cancer-associated genes such as ELF3, EHF, ACVR2A, PSIP1, CHRM3, HIST1H2AG, KAT8, and ZNF107. Previous studies on GBC reported TP53, KRAS and ERBB3 as significantly mutated GBC genes (SMG)6, though low-frequency mutations were observed in other SMG GBC genes reported in this study6,7,20.