Cymbaluk et al. noted a substantially larger average concentration of leptin (p < 0.0001) in the serum of patients with endometrial cancer and endometrial hyperplasia on the level of 16,737.1 pg/mL vs. 9048.7 pg /mL in female patients without an established pathology within the endometrium (control) [11]. Here, LEP is linked to endometrial cancer.