CD4 and acquired polycythemia vera: Levels of naïve CD4+ were significantly elevated in sensitized NSG-AD versus NSG-PV mice (P = .01, ANOVA) and in the NSG-AD and NSG-PV models; higher levels of naïve CD4+ T cells were observed upon sensitization with DMSO (AD control vs AD DMSO: P = .02; PV control vs PV DMSO: P = not significant, ANOVA).