CFAP144 is a microtubule inner protein (MIP) that localizes to the axonemal B tubule inner sheath of dynein-decorated doublet microtubules (DMTs) in motile cilia and flagella. As part of the motile cilia transcriptional signature, CFAP144 is essential for coordinating ciliary axoneme structure and function 1. The protein plays a critical role in enabling motile cilia beating, the characteristic metachronal movement of ciliated epithelial cells 1. CFAP144 is particularly relevant to flagellated sperm motility, where proper axonemal organization is required for male fertility. Mutations or dysfunction of CFAP144 and related axonemal proteins contribute to the ciliopathies—a diverse group of genetic disorders affecting embryogenesis and tissue homeostasis 1. Conditions arising from defective motile cilia include primary ciliary dyskinesia, characterized by impaired mucociliary clearance and reduced sperm motility. Given CFAP144's structural role in organizing dynein-decorated microtubules and its co-expression with FOXJ1 in motile ciliated tissues, variants in this gene likely cause motile ciliary dysfunction. Understanding CFAP144's precise molecular interactions within the axonemal lattice may inform therapeutic strategies for ciliopathies, though clinical validation in patient cohorts is needed.