TNS1 and Cowden disease: Based on RA/RAR-dependent gene profiling in CD cells21, we hypothesise that decreased RA/RAR activity in CD cells may reduce expression of focal adhesion complex components tensin (Tns1) and α2-integrin (Itga2), and the cilium-specific transcription factor Foxj1 (Foxj1), impair signalling through focal adhesion complexes and cilia, leading to disease progression.