For example, proprotein convertase subtilisin/kexin type 9 serine protease (PCSK9) inhibitors, a newer class of drugs used to treat hypercholesterolaemia, have also been shown to lower the levels of circulating ceramides and other sphingolipids [37], and can be safely combined with statins [38,39]. This evidence concerns the gene PCSK9 and Hypercholesterolemia.