We suggest that a number of different axoneme-associated proteins—including CFAP20, PACRG and others at or near the inner junction—should be investigated not only for potential roles in human cilium motility and involvement in PCD, but also for associations with non-motile cilium signalling and ciliopathies, including but not restricted to retinitis pigmentosa. The gene discussed is PACRG; the disease is retinitis pigmentosa.