After a lull last year, the good news on stem cells is flowing fast again. Sunday’s announcement by scientists in Edinburgh and Toronto that they could safely turn a fragment of skin into all-purpose stem cells follows encouraging developments on the political and regulatory fronts, notably the US Food and Drug Administration’s authorisation of the first clinical trial of embryonic stem cells (to treat spinal injury).

The scientific excitement is focused on “induced pluripotent stem cells” or iPS cells. (What a shame scientists can’t come up with catchier names.) The process would have seemed like biochemical magic just a few years ago: take adult cells, add genes and, hey presto, you have reprogrammed the cells back to an embryonic state, without involving an actual embryo. In principle these iPS cells can then be directed to become any human tissues you want, to repair failing organs from the heart to the brain.