1.   In December, Millennium Pharmaceuticals Inc. of Cambridge claimed it too had filed for worldwide patent rights for the discovery of the leptin receptor.

2.   Obese people might have a mutation in the leptin receptor, Tartaglia said.

3.   Scientists at Hoffman-LaRoche are now randomly screening compounds that bind to the leptin receptor.

4.   The fat cells turn out leptin, which travels in the bloodstream and reaches the leptin receptor in the hypothalamus, where the signal is read.

5.   This could be explained by defective leptin receptors in the brain, which would likely be controlled by a different gene.