As noted above, CT38 plasma concentrations below 0.25 ng/ml do not activate G proteins in healthy subjects, and thus the elevated hemodynamic response that occurred below 0.25 ng/ml in ME/CFS patients (Figures 4A,C), likely represents elevated constitutive (agonist-independent) activity, putatively due to increased receptor expression (Black et al., 2016; Berg and Clarke, 2018). The gene discussed is FTHL17; the disease is myalgic encephalomeyelitis/chronic fatigue syndrome.