What does the field need to move forward now?
It needs controversy.
The field of cancer stem cells needs controversy?
That's a little tongue in cheek. But it does. Controversy sparks better and better science. What it does is it actually eliminates sloppy thinking. There's been a real rush onto the cancer stem cell bandwagon in the last couple of years. People are talking about cancer stem cells here, there and everywhere, and in any old cell line. There was a huge slippage in the kind of criteria and rigor. People were using this terminology without any thought or any rigor based on some cell-surface marker or something like that. .....[Thanks to Alexey Bersenev, via Twitter/cells_nnm].