Headlines scream successful use of umbilical cord blood stem cells

But you probably didn't hear about this amazing achievement because the stem cells the scientists used to build a human liver did not come from embryos: They came from umbilical cord blood. 

This made their scientific achievement politically incorrect. A story that doesn't validate the stem-cell mantra that embryonic stem cells offer the "best hope" for future cures isn't worth much attention. Even the most important adult or umbilical cord blood stem-cell breakthroughs usually receive only minor, inside-the-paper coverage.