PCSK9 and ocular melanoma: Notably, although OM induced transient phosphorylation of STAT proteins, the suppressive effect on PCSK9 was mediated by the MEK1/ERK signaling pathway downstream of JAK, as confirmed both in vitro and in hypercholesterolemic hamsters where OM treatment reduced liver PCSK9 mRNA by 69% and protein by 41% [21, 69].