CD24 and pancreatic neoplasm: Because pancreatic CSCs can form pancreatic cancer spheroids and express CD44, CD24 and EpCAM/ESA [20,55,56], we first isolated pancreatic CSCs from the human PANC-1 pancreatic cancer cell line, based on their ability to generate pancreatic cancer spheroids in a serum-free medium containing well-defined growth factors and their enrichment in CD44, CD24 and EpCAM (Figure 1a).