Granulocyte colony stimulating factor (G-CSF) is a polypeptide with growth factor and cytokine properties that stimulates granulocyte and stem cell production from the bone marrow and promotes neovascularization following ischemia [47, 48].  In mice studies, G-CSF has been shown to prevent damage to microvessels and significantly reduce destruction of primordial follicles caused by the alkylators cyclophosphamide and busulfan [49].  Additionally, next generation breeding showed no adverse effects in the offspring.   G-CSF has also been shown to be protective against the effects of Cisplatin in mice models with improvement in follicular number and AMH levels [50].  It is postulated that with neovascularization, G-CSF decreases chemotherapy-related blood vessel loss and the associated focal ischemia seen in chemotherapy-related follicle loss [51].  Potential direct effects on the follicle remain unclear however anti-apoptotic mechanistic action of G-CSF have been proposed [52, 53].  The advantage of G-CSF over other agents is that it is currently used in cancer patients for prevention of chemotherapy-induced neutropenia and has been shown not to reduce the efficacy of chemotherapeutic agents.  Further studies are warranted to establish the specific mechanism of action and optimal timing and dosage of G-CSF during chemotherapy in humans.