PIK3CA and carcinoma of esophagus: Idiopathic achalasia and megaesophaus patients, with or without esophageal carcinoma, described changes in expression of proteins such as p53, p16, and MIB (mindbomb homolog) [63–68], chromosomal aneuploidies [59, 69], gene deletions in significant (TP53) [69] or marginal levels (TP63, FHIT, PIK3CA, EGFR, CDKN2A, and YES) [70], and gene copy number gain (PIK3CA, TP63, FGFR1, MYC, CDNK2A, and NCOA3) mainly associated with dilation grades III and IV [70].