PIK3CA and gastric cancer: In addition, the KEGG analysis revealed a total of 165 pathways (Figure 6D), including cancer, chemical carcinogenesis—receptor activation, the PI3K-AKT signaling pathway, microRNAs in cancer, focal adhesion, the Rap1 signaling pathway, resistance to EGFR tyrosine kinase inhibitor, the HIF-1 signaling pathway, the thyroid hormone signaling pathway, the Ras signaling pathway, the relaxin signaling pathway, the phospholipase D signaling pathway, and gastric cancer.