S100B and skin neoplasm: Additionally, the potentially oncogenic HIV proteins tat and nef, which disrupt MHC signaling and chemokine production [49], the high incidence of HPV infection and its possible role in the pathogenesis of SCC [23,50,51], and elevated interleukin levels that promote keratinocyte and melanocyte proliferation could all serve as cofactors in the onset of skin cancers [44].