DPP4 and malignant colon neoplasm: CD133 has been used as a putative stem cell marker in glioblastoma [9] and colon cancer [10], CD34 expressing tumor epithelial cells as CSCs in cutaneous cancer [11], CD44 expressing cells in breast cancer [12], CD26 positive cells are involved in the process of metastases, invasiveness and chemoresistance in colon cancer [13], CD271 positive cells initiate melanoma progression and metastasis [14] and properties of CSCs were identified in CD24 positive pleural mesothelioma cells [15].