Has an essential role in the assembly and organization of the sperm flagellar axoneme (PubMed:32791035). Required for the elongation of the primary cilium and sperm flagellar midpiece via modulation of the Notch signaling pathway (PubMed:31904090). Interacts with ODFP2. Localized to the entire flagellum and predominantly concentrated in the midpiece. Co-localizes with ODFP2 at the centrosome. Predominantly expressed in the testis (PubMed:32791035, PubMed:31904090). Also found at lower levels in ciliated cells and tissues such as neural progenitor cells and oviducts (PubMed:31904090). Male mice are infertile with severely decreased sperm motility and abnormal sperm flagellar morphology. Belongs to the CFAP58 family.