The mean of IGHA2 is 0.454 for controls without IBS, 0.454−2.048 = − 1.594 for ME/CFS cases without IBS, 0.454−2.811 = − 2.357 for controls with IBS, and 0.454−2.048−2.811 + 3.467 = − 0.938 for cases with IBS. Here, IGHA2 is linked to myalgic encephalomeyelitis/chronic fatigue syndrome.