PIK3CA and esophageal cancer: The esophageal cancer cell lines KYSE150, HKESC-1, KYSE270, and T.Tn were exposed to different concentrations of wortmannin or LY294002, and the results from MTT and colony-formation assays showed that blockade of PI3K/AKT pathway inhibited proliferation (Figure 3) and colony-formation ability (Figure 4) of esophageal cancer cells, suggesting that specific inhibitors of PI3K may have antitumor effects.