Betterhumans reports on a successful attempt to get bone marrow stem cells to form liver cells. Scientists are making progress in understanding how to use various types of adult stem cell to promote regeneration, but it is clear from the number of contradictory studies that we do not yet understand all the mechanisms and limitations involved. Other, related progress in this field has been noted at Fight Aging! and by Randall Parker at FuturePundit. With greater funding and more research, all that is currently mysterious will become known in the years ahead. Understanding human biochemistry is the path to ever better medicine - and thus longer, healthier lives.