 Some men have used weights to stretch the skin of the penis to regrow a foreskin; the resulting tissue does cover the glans but does not replicate the features of a foreskin.Other cultural or aesethetic practices include genital piercings involving the foreskin and slitting the foreskin.Foreskins obtained from circumcision procedures are frequently used by biochemical and micro-anatomical researchers to study the structure and proteins of human skin.