Analysis of human Dsg3-specific B cell subpopulations (total CD19+ B cells, CD19+CD27− B cells, CD19+CD27+ memory B cells, and CD19+CD27hiCD38hi plasmablasts) was performed in peripheral blood of 14 clinically well-defined PV patients in either complete or partial clinical remission, or with relapsing disease (Supplementary Tables 1, 2). This evidence concerns the gene CD19 and acquired polycythemia vera.