HIF1A and endometrial cancer: In a study where immunohistochemical expressions of leptin, Ob-R and hypoxia-inducible factor-1α (HIF-1α) were analyzed in endometrial cancer tissue, immunoreactivity for leptin and Ob-R protein was observed in 56.7% and 30.0% of endometrial cancer cases, respectively (Koda et al., 2007).