PCSK9 and atherosclerosis: Although PCSK9 and its inhibition have been principally studied in atherosclerosis and cardiovascular disease [17–20], a growing number of reports suggest a role of PCSK9 in cancers [26–30], not only as a cholesterol supplier, but also as an immune response down-regulator, by triggering degradation of the Major Histocompatibility Complex 1 (MHC-I) receptor [31–33].