LDLR and viral infectious disease: Graphical abstract: the function of proprotein convertase subtilisin/kexin type 9 (PCSK9) in reducing cholesterol uptake and low-density lipoprotein receptor (LDLR) recycling in various viral infections, including hepatitis C virus (HCV), human immunodeficiency viruses (HIV), dengue virus (DENV), rift valley fever (RVF), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is summarized in this figure