Our observation that Tax+ exosomes can be detected in the CSF of HAM/TSP patients suggests exosomal transference of HTLV-1 antigens to antigen presenting cells (APCs) may also occur in the CNS, and could play a role in perpetuating neuroinflammation in HAM/TSP through damage to various CNS resident cells such as astrocytes, microglia or oligodendrocytes (Fig. 7). Here, CNTN2 is linked to tropical spastic paraparesis.