In contrast, Schor et al. [56], in a case-control study, reported the absence of association between single nucleotide polymorphisms of pro- and anti-inflammatory cytokines (TNFA −308G/A, IL6 −174G/C, IFNG +874T/A, TGFB) and HAM patients from Brazil. Here, IL6 is linked to tropical spastic paraparesis.