Zulu et al. [23] found that low systemic concentrations of IGF-1 in early postpartum may lead to ovulation failure and the subsequent development of cystic follicles, while Vanholder et al. [24] discovered that reduced serum insulin content in early postpartum may play a part in ovarian function disturbance (i.e., cyst formation). The gene discussed is IGF1; the disease is cyst.