We found that known regulators of ACE2—HNF1B (23) and FOXA2 (24)—were up-regulated in 6 out of 8 Barrett's esophagus transcriptomic studies (Supplementary Table 2), suggesting that they may be involved with the pH-induced ACE2 expression in Barrett's esophagus. The gene discussed is ACE2; the disease is Barrett esophagus.