DPP4 and infection: To confirm CD4+ CCR4+ CD26− as the main reservoir of infection burden in patients with non‐ATL HTLV‐1 infection, CCR4−, CCR4+ CD26+, and CCR4+ CD26− subsets of CD4 T cells were sorted from eight patients (Four ACs and four patients with HAM) and PVL was significantly higher in CCR4+ CD26−(Median:85.5%) compared to CCR4−(Median: 6.2%) and CCR4+ CD26+(Median:19.4%) subsets of CD4 T cells as shown in Figure 2E.