We have shown recently that in human T lymphocytes, leptin stimulates activity and expression of the endocan-nabinoid-degrading enzyme fatty acid amide hydrolase (FAAH), through STAT3 (signal transducer and activator of transcription 3) and its CRE (cAMP response element)-like transcriptional target in the FAAH promoter [Maccar-rone, M., Di Rienzo, M., Finazzi-Agro`,A., &Rossi,A. (2003) J. Biol. Chem. 278, 13318–13324]. We have also shown that progesterone, alone or additively with leptin, up-regulates theFAAHgene in human T-cells, through the Ikaros transcription factor [Maccarrone, M., Bari, M., Di Rienzo,.