ARL13B and autosomal dominant polycystic kidney disease: Here, we observed an ~3.2 fold increase in cilia length with the progression of ADPKD (5.7 ± 0.4 μm for 2 months and 18.4 ± 1.2 μm for 4 months post-treatment) with Arl13b-EGFPtg:cPkd2 mice, whereas cilia length from control littermates did not differ substantially over the same time course (3.8 ± 0.16 μm and 4.5 ± 0.2 μm, respectively).