CFAP70 (cilia and flagella associated protein 70) is an axoneme-binding protein essential for ciliary motility regulation and flagellar biogenesis. As a component of the central apparatus C2a projection 1, CFAP70 anchors at the base of the C2a projection and interacts with CFAP65 and MYCBPAP to maintain axonemal structure 2. During spermiogenesis, CFAP70 stabilizes QRICH2, promotes cytoplasmic preassembly of CFAP61 and CFAP91, and regulates manchette localization of axoneme-associated proteins including IFT88, DNAI1, and CFAP61 3. CFAP70 deficiency causes multiple morphological abnormalities of the flagella (MMAF), characterized by club-shaped sperm heads, abnormal flagellum biogenesis, and manchette disassembly 4. Loss of CFAP70 reduces outer dynein arm (ODA) markers and central pair complex components, impairing both flagellar assembly and stability 5. Biallelic CFAP70 mutations lead to severe astheno-teratozoospermia and male infertility classified as spermatogenic failure 41 35. CFAP70-associated infertility can be partially overcome through intracytoplasmic sperm injection (ICSI), making CFAP70 a valuable diagnostic target for male infertility with oligo-astheno-teratozoospermia 3.