AMBRA1 and Cowden syndrome 1: Our observation of increased proliferation in AMBRA1-perturbed cells (AMBRA1+/−, −/−, Q30R A/G, Q30R G/G) confirmed the hyperproliferative potential of the AMBRA1 Q30 mutation, which could possibly be responsible for the benign self-limited growth of hamartomatous lesions in CS patients [16,17].