Leptin treatment induced cancer cell proliferation in six different endometrial cancer cell lines, by which: (i) Ishikawa, (ii) ECC-1 cell lines, both derived from well-differentiated endometrial adenocarcinoma, (iii) HEC-1A, (iv) substrain HEC-1B derived from moderately differentiated endometrial adenocarcinoma, (v) RL95-2 derived from moderately differentiated adenosquamous carcinoma of the endometrium, and (vi) AN3CA derived from undifferentiated endometrial adenocarcinoma [201]. This evidence concerns the gene LEP and cancer.