The purpose of this review is to examine the potential role of molecular mimicry in the pathogenesis of human T-lymphotropic virus type 1 ((HTLV- 1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP)). Comp- hensive reviews on the pathogenic mechanisms of HTLV-1-associated human diseases are available throughout the medical literature (Bangham 2000, 2003; Barmak et al. 2003; Jacobson 2002; Levin and Jacobson 1997; Nagai and Osame 2003; Osame 2002). Approximately 25 years ago the ?rst human retrovirus, HTLV-1, was isolated (Poeisz et al. 1980). Subsequently, infection with HTLV-1 was...