CYP1A2 and acute liver failure: Chowdhary et al. (2017) found that miR-122 is down-regulated in liver biopsy specimens of patients with acute liver failure (ALF) and acetaminophen (paracetamol) treated mice, suggesting that acute liver injury suppresses miR-122 expression since it protects mice and human hepatocytes from acetaminophen toxicity by regulating cytochrome P450 family members expression. To determine whether miR-122 can modulate AhR and CYP1A2 expression, they transfected miR-122−/− hepatocytes in culture with miR-122 mimic and confirmed that ectopic miR-122 suppressed AhR and CYP1A2 RNA levels.