Given that disturbed cholesterol metabolism is often associated with different etiologies linked to chronic liver dysfunction, including obesity, insulin resistance, type 2 diabetes, NAFLD, as well as viral infections and liver cancers, it will be important to clarify if PCSK9 inhibition counteracts or contributes to pathophysiology in chronic liver diseases. The gene discussed is PCSK9; the disease is obesity due to melanocortin 4 receptor deficiency.