PCSK9 and homozygous familial hypercholesterolemia: In addition, there is a great diversity in their responsiveness to statins and proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors among patients with HoFH, which is not the case in patients with HeFH; thus, we need to suspect patients as HoFH when there is a poor response to PCSK9 inhibitors.4