What is the type of introduction here: if you have a weight problem, you have more than your diet or gym to thank. you also owe a nod to your leptin gene. And while youre at it, tip a hat to your MC 4 receptors and your PC 1 enzymes and your POMC peptides. Hard to figure out the role this alphabet soup of stuff plays in helping keeping you thin? Don't feel bad. Its all new to scientists too.