In the subsequent analysis, mechanisms underlying increased ALT levels during co-administration of tocilizumab and acetaminophen were investigated by simulating two scenarios: co-administration including tocilizumab-mediated inhibition of explicitly modeled IL-6 signaling only (changes in CYP activity, hepatocyte regeneration, macrophage recruitment, and IL-6 cross-signaling effects) and co-administration including tocilizumab-mediated steatosis and ROS elevations only. The gene discussed is IL6; the disease is steatosis.