ORAI1 and esophageal cancer: These findings support two possibilities: 1) the expression of STIM1 is so abundant in esophageal epithelial cells and thus it is sufficient to cope with the regulatory needs even in the case of significant elevated expression of Orai1 in esophageal cancer cells; 2) STIM1 is not sufficient to support the regulatory needs so that some Orai1 channels may escape coupling with STIM1.