Amongst the possible regulators, several small GTPases have been associated with the flagellum: ARL-13b is involved in the stabilization of ciliary assembly in C. elegans and its mutations are associated with a ciliopathy named Joubert syndrome (Cantagrel et al., 2008; Cevik et al., 2010; Li et al., 2010). This evidence concerns the gene ARL13B and ciliopathy.