KITLG and Infertility: Previous studies found that this pathway was regulated by SCF in GCs, which was vital for early follicular development, and its blockage resulted in impaired follicular development and infertility.[12,13] In vitro co-culture of mouse oocytes and SCF showed that SCF substantially promoted the extrusion of the first polar body in preovulatory oocytes and promoted follicle development and maturation.