Cilia from patients with PCD variants in genes coding for DNAAFs have absent ODA and IDA ciliary dynein arm proteins — including DNAH5, DNAI1, DNALI1, and DNAH7 — in ciliary axonemes; however an unbiased analysis of proteins in the variant ciliary axoneme has not been performed (10, 27). The gene discussed is DNAI1; the disease is primary ciliary dyskinesia.