Recently, proprotein convertase subtilisin/kexin type 9 (PCSK9), which increases blood LDL level by binding and preventing LDLR recycling, is also reported as related to the CAVD prevalence10, and PCSK9 loss-of-function mutation is reported to decrease the incidence of AS11,12. This evidence concerns the gene PCSK9 and congenital bilateral aplasia of vas deferens from CFTR mutation.