HTLV-1 infects hCMEC/D3 cells via their receptors for viral entry, Glut-1 and neuropilin-1, an observation that has been confirmed in situ in necropsy material from patients with TSP/HAM (tropical spastic paraparesis/human T-lymphotropic virus type-I-associated myelopathy)[3]. This evidence concerns the gene SLC2A1 and tropical spastic paraparesis.