CFAP20 is a ciliary protein with dual roles in axonemal structure and transcription-replication coordination. As a microtubule inner protein within dynein-decorated doublet microtubules, CFAP20 is essential for motile cilia beating and axonemal integrity 1. It regulates cilia size and morphology through its involvement in axonemal microtubule polyglutamylation 2. Beyond cilia, CFAP20 maintains structural integrity of inner junctions in non-motile cilia, influencing sensory signaling 3. Notably, CFAP20 functions in transcription-replication coordination by salvaging arrested RNA polymerase II from replication fork paths, preventing R-loop accumulation and maintaining genome stability 4. CFAP20 cooperates with BROMI, CCRK, and FAM149B1 in regulating intraflagellar transport turnaround at the ciliary tip 5. Clinically, CFAP20 mutations cause retinal dystrophy in both human patients and zebrafish 3, with a homozygous variant (c.337 C>T) identified in autosomal recessive retinitis pigmentosa, suggesting CFAP20 as a candidate retinopathy gene 6. These findings reveal CFAP20 as a multifunctional protein linking ciliary dysfunction to vision loss and genome stability.