LEP and obesity due to melanocortin 4 receptor deficiency: One possible explanation may be that obesity has been identified as a risk factor for cells undergoing EMT through a leptin-associated pathway.53,54 Similarly, the histological finding of TB has been described as portions of the tumor undergoing EMT, likely related to β-catenin dysregulation.20,55,56 TB has also been described as having very similar properties as groups of cancer stem cells (CSCs) and may represent a subset of migrating CSCs.