(20) reported that there is a large amount of mononuclear macrophage infiltration in the skin lesions of patients with syphilis and rabbit models, and the level of the macrophage activator IFN-γ was significantly increased, along with the upregulation of the macrophage activation markers CD68, CD80, and CD86 in secondary syphilitic lesions (21). Here, CD86 is linked to syphilis.