ZEB1 and breast cancer: The fusion of prostate cancer cells with muscle cells increased the number of CD133+ stem-like cells.194 Hybrids from fusions of non-malignant human breast epithelial cells and breast cancer cells exhibit CSC properties,195 which is dependent on the transcription factor Zinc Finger E-Box Binding Homeobox 1 (ZEB1).196 Hybrids from tumor-associated macrophages and breast cancer cells also exhibit CSC phenotype and promote cancer metastases in a mouse model.197 Furthermore, CSCs can also fuse with other cells and obtain higher malignancy.