PIK3CA and gastric adenocarcinoma: Five of the above 10 genes were reported to participate in STAD progression, pathogenesis, immune microenvironment, and malignant transformation, which were PIK3CA, SPECC1, ARID1A, ZBTB20, and KMT2D (Wang et al., 2011; Shi et al., 2017; Xiong et al., 2018; Ashizawa et al., 2019; Chen et al., 2019; Seo et al., 2019), and were related to the prognosis and survival for patients.