Keratin and Langerhans cells    The material on keratin and Langerhans cells got deleted somehow Id like to put it back in  I think its important because it explains a possible reason why circumcision might help protect against a number of diseases in the case of keratin and HIV in particular in the case of Langerhans cells Otherwise were only presenting dry statistics We can now cite a secondary source for this theory the WHO document I suggest the following  According to the WHO the layer of keratin on the inner surface of the foreskin is thinner than on the shaft of the penis which may make it easier for pathogens to enter and cells targetted by HIV are also closer to the surface on the inner foreskin p