This is further validated by the data on absence of expected JAK2 V617F and CALR Type 1/2 type mutations in the monoclonal gammopathy-associated PRCA cohort reported by Korde et al. (2) eliminating the dysfunctional EPOR mediated JAK2-STAT5 pathway circuitry. The gene discussed is EPOR; the disease is pure red-cell aplasia.