Overall, plasma concentrations of IL4RA were elevated in the DCM cohort compared with controls (DCM NPX median 2.63 [IQR: 2.38-2.93], control NPX median 2.55 [IQR: 2.31-2.72]; P = 0.037) (outlined further in Supplemental Methods and Supplemental Table 7). Here, IL4R is linked to familial dilated cardiomyopathy.