As IL-8 is also a pro-angiogenic chemokine (Li et al., 2003), up-regulation may contribute to the vascular inflammation and increased angiogenesis observed during secondary syphilis (French, 2007; Gao et al., 2019) and may promote treponemal accessibility to the host’s circulatory system via proliferation of endothelial cells and formation of new blood vessels, similar to the mechanism proposed for the IL-8-inducing T. pallidum protein TpF1 (Pozzobon et al., 2016). This evidence concerns the gene CXCL8 and syphilis.