In cystic fibrosis (CF), large copy number variants (CNVs) such as deletions and duplications account for 8.7% (102 out of 1167 (25/09/2024)) of all CFTR variants recorded in the CFTR2 database (https://cftr2.org/mutations_history (accessed on 22 April 2025)) and for 1.4% (76 out of 5422 of all CFTR variants in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar (accessed on 12 March 2025)). Here, CFTR is linked to cystic fibrosis.