Familial hypercholesterolaemia (FH) is a devastating disease that leads to extremely high cholesterol levels and severe cardiovascular disease. The severe homozygous variety (HoFH) is not successfully treated with standard cholesterol-lowering therapies. Because HoFH is mainly due to mutations in the LDLR, this disease has been proposed as an ideal candidate for gene therapy. Several preclinical studies have shown that the transference of functional copies of the LDLR gene reduces circulating LDL-C levels in several models of HoFH. The recent development of the CRISPR/Cas9 technology has opened the door to strategies aimed at directly correcting the specific mutation in the endogenous LDLR gene. (By Dr. Ricardo Rodríguez-Calvo, https://jmg.bmj.com/content/early/2019/03/15/jmedgenet-2018-105713 )