“HLA-unmatched” controls expressed very low levels of several cytokines (IL-1α: 12.01 ± 23.9 pg/mL, IL-1β: 2.55 ± 5.2 pg/mL, IL-6: 3.12 ± 5.2 pg/mL, TNFα: 10.22 ± 5.8 pg/mL, IL-8: 142.21 ± 162.9 pg/mL, and IL-13: 7.31 ± 14.1 pg/mL, respectively), while “HLA-matched” controls expressed levels on par or greater than those found in PV patients for numerous cytokines (IL-1α: 41.35 ± 96.6 pg/mL, IL-1β: 26.03 ± 65.7 pg/mL, IL-6: 115.8 ± 297.9 pg/mL, TNFα: 45.51 ± 85.0 pg/mL, IL-8: 1076.47 ± 2587.9 pg/mL, and IL-13: 18.7 ± 44.4 pg/mL, respectively) (Figure 2A and Tables 3A, B). This evidence concerns the gene IL13 and acquired polycythemia vera.