The complete gene sequences of 23 Gastric cancer genes were retrieved from the PDB with the subsequent PDB ID MULT (IBKN), CTTNA (1DOV), CDKNA (1G3N), MUTHY (1RRS), TRET (2B2A), PIK3A (2ENQ), APC (1DEB), BRCA2 (8HQU), TP53 (1A1U), PTEN (7JVX), ERBB2 (50B4), EGFR (2N5S), POLE (5VBN), RAD51D (2KZ3), SMAD4 (1YGS), FGFR2 (1DJS), DICER-1 (2EB1), THBS2 (1YO8), ABCG2 (5NJ3), MET (5LSP), BRAF (1UWH), CDH1 (2O72) and COL1A1 (1Q7D). The gene discussed is SMAD4; the disease is gastric cancer.