Smegma

Smegma is a secretion of the sebaceous glands[?] composed primarily of desquamated (shed) epithelial[?] cells which typically collect under the prepuce (foreskin of the penis) or around the clitoris. It is whitish-yellow in appearance and emits a pungent odor. There are numerous university studies that demonstrate that HPV (Human Papiloma Virus), a causitive agent in cervical cancer grows well in smegma. It is also found on the skin of newborn infants.

As suggested by its etymological roots in the Latin word for "detergent" (ie, soap), smegma provides both cleaning and lubrication functions.