Thus, the present study evaluated the association of the NGF -198C/T (rs11102930), NGF Ala35Val (rs6330), and p75NTR Ser205Leu (rs2072446) polymorphisms with HTLV-1 infection, the presence of diseases associated with infection, proviral load, and plasma levels of the cytokines TNF-α, IFN-γ, and IL-10. Here, TNF is linked to infection.