DNAH7 (dynein axonemal heavy chain 7) is a force-generating motor protein essential for ciliary and flagellar motility. As a component of the inner dynein arm (IDA) complex, DNAH7 produces force directed toward the minus ends of microtubules through ATP hydrolysis, with power generation occurring upon ADP release 1. The protein plays critical roles in maintaining axonemal structure and coordinating ciliary beating in respiratory epithelium and sperm flagella. Mechanistically, DNAH7 is a light intermediate chain-binding protein within a partial IDA subspecies 2. Cryo-EM studies reveal that DNAH7 contains an 18-residue insertion that contacts adjacent microtubule protofilaments and uniquely induces microtubule cross-sectional distortions, potentially mediating dynein coordination in axonemes 1. Biallelic loss-of-function DNAH7 variants cause primary ciliary dyskinesia (PCD) and male infertility characterized by asthenozoospermia 3. In infertile men, DNAH7 mutations result in severe loss of inner dynein arms in sperm flagella, accompanied by mitochondrial abnormalities and reduced expression of associated IDA proteins (DNAH3, DNAH6) 43. Clinically, intracytoplasmic sperm injection successfully achieves live birth in DNAH7-deficient patients, enabling reproductive outcomes despite flagellar dysfunction 4. Additionally, DNAH7 variants show potential association with testicular germ cell tumor susceptibility 5.