The loss of contact inhibition is a hallmark of cancer cells.4 The Hippo pathway is an important regulator of cell-contact inhibition.5, 6, 7 A very close relationship between polarity proteins and Hippo pathway components has been established over the past few years.5, 40 CRB3 has been shown to regulate growth arrest via contact inhibition.21 Additionally, Crb acts as an upstream regulator of the Hippo pathway in Drosophila.5 However, researchers have not yet determined whether CRB3 (the homologue of Drosophila Crb) regulates contact inhibition through the Hippo pathway. This evidence concerns the gene CRB3 and cancer.