For example, in non-classical monocytes from PV patients, T cell activation genes were strongly upregulated, including HLA-DPA1, HLA-DPB1, CD74, EGR1, HLA-DRA, HLA-DRB1, HLA-DMB, ZFP36L1, and IL1B. The gene discussed is HLA-DPA1; the disease is acquired polycythemia vera.