[3] It forms in the ventral, caudal region of mammalian embryos of both sexes, and eventually develops into a primordial phallus.

This should not be confused with the sinus tubercle which is a proliferation of endoderm induced by paramesonephric ducts.

Even after the phallus is developed (either a penile shaft or clitoral shaft),[4] the term genital tubercle remains, but only as the terminal end of it,[5] which develops into either the glans penis or the glans clitoridis.

[6] In the female fetus, the tubercle is attached to the vestibular folds that remain unfused forming the labia minora and the vaginal vestibule in between.

[7] The genital tubercle is sensitive to dihydrotestosterone and rich in 5-alpha-reductase, so that the amount of fetal testosterone present after the second month is a major determinant of phallus size at birth.