ACE and esophageal squamous cell carcinoma: On the one hand, RAS factors, such as angiotensin-converting enzyme (ACE) and the angiotensin II subtype 1 receptor (AT1R), seem to be upregulated in Barrett’s esophagus [68] but, on the other hand, no prognostic effects of RAS-inhibition have been found in both ESCC and EAC so far [69].