Because information on the role of TLR7 in HTLV-1 infection is limited, and there is lack of studies on the influence of genetic variations in the TLR7 gene on infection, in the present study, the associations of TLR7 rs179008 (A/T) and TLR7 rs3853839 (C/G) with susceptibility to HTLV-1 infections, the presence of symptoms of inflammatory diseases associated with infection, TLR7 gene expression, IFN-α, inflammatory cytokines and the proviral load were investigated. This evidence concerns the gene IFNA17 and infection.