Hh signaling promotes the removal of the orphan G protein coupled receptor GPR161 from the cilium (Rohatgi et al, 2007). GPR161 is a negative regulator of Hh signaling that is recruited to the cilium through interaction with TULP3 (Mukhopadhyay et al, 2010; Mukhopadhyay et al, 2013). GPR161 thought to act by locally increasing the cAMP levels, promoting PKA activity and thereby favouring the production of the repressor form of the GLI proteins in the absence of Hh ligand. Consistent with this, deletion of GPR161 results in ectopic pathway activation (Mukhopadhyay et al, 2013). The decrease in PKA activity in the cilium after clearance of GPR161 from the ciliary membrane may contribute to the dissociation of the GLI:SUFU complex upon pathway activation, although this remains to formally demonstrated (Humke et al, 2010; Tukachinsky et al, 2010; reviewed in Mukhopadhyay et al, 2014).