Compelling biological reasons explain the vulnerability of the foreskin to HIV infection.80, 227, 228, 229, 230, 231 Infectivity is exacerbated in inflammatory states and ulceration from sexually transmitted infections (STIs),232, 233, 234, 235, 236 coital injuries (more common in uncircumcised men),127, 128, 129 and foreskin size.159 Langerin, produced by the mucosal epithelium of the foreskin, is protective at low viral loads,237 but becomes overwhelmed at high HIV loads.237, 238. Here, CD207 is linked to sexually transmitted disease.