Peroxisome proliferators are non-genotoxic carcinogens which are purported to exert their effect on cells by interacting with members of the nuclear hormone receptor superfamily known as peroxisome proliferator activated receptors (PPARs). There are four of these nuclear hormone receptors known to date, and they are ligand-dependent intracellular proteins that stimulate downstream gene transcription of genes such as acyl coenzyme A oxidase and cytochrome P450 (CYP450). Activation occurs through direct binding to specific DNA response elements following activation by an appropriate ligand.
