CCDC40 and male infertility: According to a systematic review of the validated monogenic causes of human male infertility by the International Male Infertility Genomics Consortium (IMIGC) in 2020, eight PCD‐related genes are at least moderately linked to male infertility, namely, CCDC39, CCDC40, DNAAF2, DNAAF4, DNAAF6, LRRC6, RSPH3 and SPEF2.17