HBZ and tropical spastic paraparesis: Among all genes upregulated by both Tax and Hbz overexpression, we found significant enrichment of several pathways shared with our HAM findings (Fig. 4C): metabolic pathways (pyruvate, steroids, fatty acids) as well as immune pathways (antigen presentation, Th17 activation) and estrogen signaling (in agreement with female predominance in HAM).