We suggest a causal relationship for HEV and IC-MPGN due to biological plausibility and coherence: in particular 1) the co-localization of HEV ORF2 protein with IgG and C3 in the glomerular lesions, accompanied by increased proteinuria, and 2) the finding of a biological gradient34. The gene discussed is C3; the disease is primary membranoproliferative glomerulonephritis.