Present in the cytoplasm of elongating spermatids of the stages IX-X seminiferous tubules while it is localizes to the nucleus of spermatozoa of the stages VII-VIII tubules and mature spermatozoa isolated from epididymis. Expressed testis, ovary, uterus, kidney, liver, but not in other tissues. Ubiquitinated by the CRL2(FEM1B) complex, leading to its degradation.