The endogenous induction of hundreds of ISGs in patients with CHC has little impact on viral replication, whereas treatment of patients with recombinant pegIFN‐α achieves high cure rates specifically in patients without an activation of the endogenous IFN system in the liver (Heim, 2013; Heim & Thimme, 2014). The gene discussed is IFNA1; the disease is cryohydrocytosis.