Recently, a Japanese group made an artificial liver from stem cells.
Sooner or later we will be able to routinely personalize new body parts to treat a range of diseases, from genetic diseases to traumatic injuries.
In another recent study, Harvard researchers restored hearing to deaf mice, using stem cells to replace lost hair cells. (hms.harvard.edu/news/hearing-restored-after-noise-damage-1-9-13)
I find this amazing, given that 20 years ago, the stem cell field seemed dead on arrival. Stem cell research used to require embryos and the political, moral, and practical problems presented by the need to destroy human embryos seemed insurmountable. Now, by simply tweaking four genetic pathways, adult cells can be reprogrammed to act like embryonic stem cells.
For the biography of one of the scientists involved in inventing these adult stem cells - or IPS cells - please click here. (Full disclosure - I made this film for the Franklin Institute.)