Stimulated exit of GPR161 from cilia is blocked in ARL3-KO, ARL13B-KO, and INPP5E-KO cells. Control RPE1 cells (A, F), the ARL3-KO cell lines #ARL3-1-18 (B, G) and #ARL3-2-6 (C, H), the ARL13B-KO cell line #ARL13B-1-2 (D, I), and the INPP5E-KO cell line #INPP5E-2-2 (E, J) were serum-starved for 24 h, and then cultured in the absence (A–E; –SAG) or presence (F–J; +SAG) of 200 nM SAG for a further 24 h, and triply immunostained for GPR161 (A–J), Ac-tubulin (A′–J′), and γ-tubulin (A″–J″). Scale bars, 5 µm. (K) Relative ciliary staining intensities of GPR161 in control, ARL3-KO, ARL13B-KO, and INPP5E-KO cells under basal and SAG-stimulated conditions are represented as scatter plots. Different colored dots represent three independent experiments, horizontal lines indicate the means, and the error bars are the SDs. Statistical significances were calculated using one-way ANOVA followed by the Tukey-Kramer test.