PCSK9 and homozygous familial hypercholesterolemia: Patients with HoFH either do not respond to traditional LLTs (for example, statins, ezetimibe, and proprotein convertase subtilisin/kexin type 9 [PCSK9] inhibitors) or have attenuated responses, as the effectiveness of these LLTs is dependent upon functioning LDLRs11–14.