CD4 and infection: Recently, it was reported that gonadectomy increases parasitemia in Pb ANKA-infected CBA/Ca mice of both sexes, and reconstituting gonadectomized mice with testosterone prevents weight loss and hypothermia caused by infection with the parasite, but affects CD4+, CD8+, and B220+ cells differently depending on sex and testosterone concentration (Aguilar-Castro et al., 2022).