Reflux (n=75), Barrett’s (n=63) and treatment naïve cancer patients (n=38) had a median PIG-A mutant frequency of 3.2 (95% CI: 1.51-5.43), 4.52 (95% CI: 2.53-6.09) and 9.75 (95% CI: 3.76-17.52) respectively. The gene discussed is PIGA; the disease is cancer.