Indeed, Anderson et al. have already reported that the demethylation rate of the Foxp3 TSDR is lower in PBMCs and CD4 + CD25+ T cells from HAM/TSP patients than in uninfected normal controls, and decreased TSDR demethylation is associated with decreased functional suppression via Tregs in HAM/TSP patients [50]. Here, FOXP3 is linked to tropical spastic paraparesis.