SELPLG and acquired polycythemia vera: To date, reduced numbers of circulating Vγ9Vδ2 T cells expressing skin-homing cutaneous lymphocyte-associated antigen (CLA) (8), and genes controlling IFN-γ/TNF signaling, T cell activation, and proliferation have been found in PV patients (19), and their transition from naïve to terminally differentiated phenotype has been linked to disease severity (19).