EurekAlert! brings news of more cancer stem cells: "The cells we isolated are quite different from 99 percent of the millions of other cells in a human pancreatic tumor, and we think that, based on some preliminary research, standard treatments like chemotherapy and radiation may not be touching these cells. If that is why pancreatic cancer is so hard to treat, a new approach might be to design a drug that specifically targets pancreatic cancer stem cells without interfering with normal stem cell function ... theory suggests that only cells that have the properties of 'stemness' - that is, cells that can self-renew and differentiate into other types of cells - are the only ones capable of producing tumors. These 'cancer stem cells,' could derive from normal adult stem cells in organs that have mutated, or from a differentiated cell that has devolved to take on the qualities of stem cells. They are resistant to traditional therapy designed for cells that rapidly turn over because stem cells don't, according to some researchers. Thus, they remain after tumors shrink and may be responsible for cancer recurrence and metastasis."