"In a mouse germline knockout of RP2 ARL3-GTP is abundant as its intrinsic GTPase activity is extremely low. High levels of ARL3-GTP impair binding and trafficking of cargo to the outer segment. This knockout is embryonically lethal causing a syndromic ciliopathy-like phenotype. The knockouts reveal binary functions of ARL3-GTP as a key molecule in late-stage photoreceptor ciliogenesis and cargo displacement. Review."xsd:string