May regulate cilium motility through its role in the assembly of the axonemal RS2 radial spoke. The mobility of cells lacking CFAP206 is decreased. If their number is normal, cilia are slightly longer and display uncoordinated motility with abnormal waveform characterized by decreased bend amplitude and decreased metachronal coordination. Cilia axonemes display a classical 9+2 organization of microtubules but their shape is abnormal. Belongs to the CFAP206 family.