MSX1 and cancer: MSX1 is crucial in controlling epithelial–mesenchymal interactions during embryogenesis [37,38], and DNA methylation of these CpGs is thought to impair MSX1-dependent mesenchymal embryogenesis [39], suggesting that hypomethylation of MSX1 plays a role in the occurrence of EMT through promoting the transition of cancer cells to a mesenchymal phenotype.