Longitudinal analysis of plasma IL-7 levels in SIVmac239-infected macaques. Six juvenile macaques—3 nonthymectomized macaques (continuous lines; RM1, magenta; RM2, dark blue; RM3, blue/gray) and 3 thymectomized macaques (broken lines; RM4, red; RM5, orange; RM6, yellow/green)—were included in the longitudinal study. (A) Plasma IL-7 levels as fold change from baseline are depicted through the disease course. Macaques that died of simian AIDS are indicated by an asterisk. (B) Plasma IL-7 levels as fold change from baseline depicted for first 35 weeks after infection to elucidate the changes occurring during the early time points.