PIK3CA and gastric cancer: The somatic mutation analysis between the low-risk and high-risk groups of GC patients found that the top 20 mutated genes in the two groups were TTN, TP53, MUC16, ARID1A, LRP1B, SYNE1, FLG, FAT4, CSMD3, PCLO, DNAH5, KMT2D, FAT3, HMCN1, OBSCN, RYR2, ZFHX4, SPTA1, PIK3CA, and CSMD1.