PPARA and hepatitis C virus infection: Studies on the role of PPARα in major human tissues and, particularly, in liver, have indicated that mRNA expression is quite similar in humans and mice and may be reduced in severe hepatic disorders, such as non-alcoholic steatohepatitis and hepatitis C. In human liver, PPARα plays a pivotal role in various metabolic processes and its activation does not promote tumor formation, as found in rodents.