Our experiments showed that from 24 h to 72 h, there were high levels of cytokines IL-6, IL-8, IL-1β, TNF, IL-10, and IL-12p70, especially in cells stimulated by the PBMCs from individuals seropositive for HTLV-1 with HAM/TSP, indicating an important role for these cytokines in the early response of the immune system to HTLV-1 infection. The gene discussed is IL10; the disease is tropical spastic paraparesis.