IL2 and tropical spastic paraparesis: Monoclonal antibody therapy in HAM/TSP using a humanized antibody to IL-2 Rα showed reduction in the proviral load and spontaneous proliferation (Lehky et al., 1998), and a clinical trial of humanized-Mik-β-1, monoclonal antibody against IL-2/IL-15 Rβ, is currently underway, with promising early results (Waldmann, 2015).