DNAAF6 (dynein axonemal assembly factor 6) is a cytoplasmic protein essential for the pre-assembly of axonemal dynein complexes required for motile cilia function 12. The protein plays a critical role in the assembly of both outer and inner dynein arms in ciliary axonemes 31. Mechanistically, DNAAF6 functions within an R2TP-like complex and colocalizes with LARP6 in biomolecular condensates called dynein axonemal particles, where it regulates α-tubulin protein expression near the apical side of multiciliated cells during ciliogenesis 2. Pathogenic variants in DNAAF6 cause X-linked primary ciliary dyskinesia (PCD), characterized by immotile cilia lacking dynein arms, leading to recurrent respiratory infections, bronchiectasis, and male infertility 34. Males with hemizygous mutations display severe PCD symptoms with exclusively immotile cilia, while heterozygous females show variable phenotypes depending on X-chromosome X patterns - ranging from asymptomatic to mild-moderate respiratory symptoms 54. Importantly, studies demonstrate that 30-62% of functioning multiciliated cells can maintain adequate ciliary clearance, suggesting potential therapeutic thresholds for gene therapy approaches 46.