RIPK1 and Hepatitis: Depending on the cellular conditions, the enzymatic activity of RIPK1 has been reported capable of mediating apoptosis or necroptosis, a regulated form of necrosis with RIPK3 and MLKL as core components.40, 41 We found that WT mice with ConA-induced liver injuries exhibited only few caspase-3-positive hepatocytes, and that pan-caspase inhibition by Q-VD-OPh failed to protect these mice from ConA-induced hepatitis, supportive of necroptosis induction.