Where are the STAP cells?

Signals Blog just posted a short commentary I wrote on STAP cells and why I think they're too good to be true:

Esophageal cancer is the end point on a spectrum of diseases. At the beginning, chronic acid reflux exposes the esophagus to the low pH levels of stomach acid, which is a risk factor for Barrett’s Esophagus. Barrett’s, in turn, is a risk factor for developing this type of cancer, which may take several decades to appear.

My original thoughts when STAP cells were first reported were that there would be a clear link between acidic conditions and stemness. ... But there’s no overwhelming evidence to suggest that that happens.

Acid reflux seems like the ideal natural experiment to prove that STAP cells exist, yet the esophagus doesn't turn into a mess of iPS cells every time someone gets heartburn.

Read on at Signals.