This multi‐layered compartmentalization is in line with previous reports demonstrating that in renal epithelial cells, PDE4 regulates cAMP‐stimulated cystogenesis (Omar et al, 2019) and PDE4C co‐localizes with the PC2/AKAP150 ciliary protein complex, which is dysregulated in ADPKD (Choi et al, 2011). Here, CBX4 is linked to autosomal dominant polycystic kidney disease.