Significant reduction in anti-DSG1 Ab levels were seen in PV patients regardless of therapy with SSA (p = 0.00023) or rituximab (p = 0.0025), whereas anti-DSG3 Abs while lower in both treatment groups were only statistically significant in rituximab treated PV patients (p = 0.00001, Fig 1). This evidence concerns the gene DSG3 and acquired polycythemia vera.