PCSK9 and familial lipoprotein lipase deficiency: Further studies of PCSK9 levels in patients with hyperchylomicronemia would be interesting in order to verify if all homozygous patients with T1HLP have low PCSK9 levels, or if it is specific to the patients in the studied family, and to decipher the causes of this decrease, as well as the mechanism, the role of PCSK9, and its correlation with ApoB levels (Ayoub et al., 2021).