Research indicates that a future path for stem cell therapies might involve manipulating the cells' immediate environment in ways that reprogram those cells in specific, controllable ways: "We found that adult human mammary stem and progenitor cells exhibit impressive plasticity in response to hundreds of unique combinatorial microenvironments. Our results further suggest that rational modulation of the microenvironmental milieu can impose specific differentiation phenotypes on normal stem or progenitor cells, and perhaps even [restore cancerous cells to normal behavior]. All of this points to the rational manipulation of adult stem and progenitor cells as a promising pathway for beneficial therapies ... Working with unique microenvironment microarrays (MEArrays) [we] can use combinations of proteins from a select tissue to create multiple microenvironments on a single chip about two square centimeters in area ... These results are exciting because they indicate that we can test a large number of effectors and determine which ones to use to direct the fate of adult stem and progenitor cells. This give hope that one day - sooner rather than later - the information could be used for therapy."