In summary, we present a list of significant differences in gene expression and have validated important examples in the PCOS endometrium that demonstrate LIF, MUC-1, and CSF-1 reduced endometrial receptivity, EGF and ANG decreased angiogenesis, IL-2, IL-2R, IL-6, IL-6R, and IL-15 increased inflammation, FASN perturbed energy metabolism, and PPARγ increased insulin resistance. The gene discussed is LIF; the disease is polycystic ovary syndrome.