Localization of KITL antigen in mouse ovaries. Immunohistochemical detection of KITL in ovaries of PMSG-primed mice at 4 h after hCG injection. (A) KITL staining; (B) negative controls. KITL was detected in granulosa cells of preovulatory (arrows) and small antral follicles (arrowheads), and weaker staining of KITL was found in interstitial cells. (Scale bars, 50 μm).