- Differential gene regulation in human versus rodent hepatocytes by peroxisome proliferator-activated receptor (PPAR) alpha. PPAR alpha fails to induce peroxisome proliferation-associated genes in human cells independently of the level of receptor expresson. Lawrence, J.W., Li, Y., Chen, S., DeLuca, J.G., Berger, J.P., Umbenhauer, D.R., Moller, D.E., Zhou, G. J. Biol. Chem. (2001)