The activation of Wnt signaling (observed in RPT monolayers with an L2HGH KD) occurs when the level of the Wnt antagonist DKK1 declines, an event which may result from the hypermethylation of the DKK1 promoter, the trimethylation of H3K27, and the recruitment of the Polycomb complex, as observed in lung cancers (67). Here, DKK1 is linked to lung cancer.