CNTN2 and tropical spastic paraparesis: Furthermore, although the chemokine CXCL10, which has been proposed as a prognostic biomarker for HAM/TSP (Sato et al., 2013), was more efficiently induced by Tax-A than by Tax-B through the nuclear factor (NF)-κB pathway, there was no difference in the ability of each subgroup of Tax (i.e., Tax-A or Tax-B) to activate the CXCL10 gene promoter evaluated using a reporter gene assay with HTLV-1-negative human T-cell line Jurkat (Naito et al., 2018).