The present invention relates generally to a nucleic acid molecule which is expressed in at least the stomach, hypothalamus or liver identified using differential display techniques under differing physiological conditions. It is proposed that the nucleic acid molecules encode expression products associated with the modulation of obesity, anorexia, weight maintenance, diabetes and/or metabolic energy levels. More particularly, the present invention is directed to nucleic acid molecules and expression products produced by recombinant means from the nucleic acid molecule or isolated from natural sources and their use in therapeutic and diagnostic protocols for conditions such as obesity, anorexia, weight maintenance, diabetes and/or energy imbalance. The subject nucleic acid molecule and expression products and their derivatives, homologs, analogs and mimetics are proposed to be useful, therefore, as therapeutic and diagnostic agents for obesity, anorexia, weight maintenance, diabetes and/or energy imbalance or as targets for the design and/or identification of modulators of their activity and/or function.