A level of anti-Dsg1 autoantibodies ≥ 100 U/mL at diagnosis was significantly associated with an increased risk for overall mortality among patients with PV (HR = 2.76 (95% CI, 1.01–7.5), p = 0.047), but not PF (p > 0.05), in the initial univariate analysis. Here, DSG1 is linked to acquired polycythemia vera.