PIK3CA and esophageal squamous cell carcinoma: Recent investigations employing whole-genome sequencing and whole-exome sequencing have revealed mutations in multiple genes, including TP53, CDKN2A, FAT1, NOTCH1, PIK3CA, KMT2D, and NFE2L2, previously linked to esophageal squamous cell carcinoma (ESCC) (Sasaki et al., 2016).