The present invention relates to mammalian nucleic acid and protein molecules comprising a plurality of nucleic acid and protein molecules. The mammalian nucleic acid molecules can be used as hybridizable array elements in a microarray in diagnostic and therapeutic applications including detecting metabolic and toxicological responses, and in monitoring drug mechanism of action. The protein molecules can be used in a pharmaceutical composition. The present invention also relates to methods for screening compounds and therapeutics for metabolic responses indicative of a toxic compound or molecule.