PIK3CA and gastric adenocarcinoma: Moreover, the relative frequencies of HMCN1 + PIK3CA as the marginal factor (blue line) and trimutation of LRP1B + HMCN1 + PIK3CA as the marginal factor (dark blue line) decreased from pathological stage II to stage III and stage IV, but the relative frequencies of LRP1B + HMCN1 dimutation (yellow line) and LPR1B + PIK3CA dimutation (green line) showed an increasing trend, indicating that mutations of HMCN1 and PIK3CA might become mutually exclusive and might not be good for the prognosis of STAD patients at these stages.