KITLG and nutritional deficiency disease: GDF-9 is essential for folliculogenesis and fertility.49 In addition, progenitor germ cells can address issues with folliculogenesis caused by malnutrition by repairing damaged follicles and can restore molecular communication in ovarian follicles by increasing the synthesis of SCF and GDF-9.21 Oogenesis can activate homing directly through the activation of cells that have been repressed and indirectly through the stimulation of the microenvironment (niche) of injured cells.50