CCDC39 and male infertility: Our synthesis confirms 18 genes with robust evidence for PCD-associated male infertility (ADCY10, ARL2BP, CCDC151, CCDC39, CCDC40, CDC14A, DNAAF1, DNAAF2, DNAAF4, DNAAF6, DNAH11, DNAH5, DNAI1, HYDIN, LRRC6, MNS1, RSPH3, RSPH4A, TTC12), highlighting shared pathways between somatic ciliary function and sperm flagellar integrity.