As shown in Fig 3b, healthy CD4+T cells and HTLV-1-infected CD4+ cells from HAM samples show a pattern of enriched nucleosome-free fragments (l < 100 bp) and mono-nucleosome fragments (l = 180 ∼ 247 bp) surrounding the TSSs, where the thresholds for the length of a fragment are 100 bp, 180 bp, and 247 bp based on a previous study [21]. This evidence concerns the gene CD4 and tropical spastic paraparesis.