ADP-ribosylation factor (ARF)-like proteins (ARLs) comprise a functionally distinct group of the ARF family of RAS-related GTPases. ARL2BP binds to ARL2.GTP with high affinity but does not interact with ARL2.GDP, activated ARF, or RHO proteins. The lack of detectable membrane association of ARL2BP or ARL2 upon activation of ARL2 is suggestive of actions distinct from those of the ARFs. ARL2BP is considered to be the first ARL2-specific effector identified, due to its interaction with ARL2.GTP but lack of ARL2 GTPase-activating protein activity. ARL2BP, together with ARL2, plays a role in the nuclear translocation, retention and transcriptional activity of STAT3. ARL2BP may play a role as an effector of ARL2.