Reprogramming of B cell acute lymphoblastic leukemia cells: Do we need to shoot a moving target?

In a recent paper, McClellan et al. (1) report that blasts from some precursor B cell acute lymphoblastic leukemia (B-ALL) cases transdifferentiate (reprogram) into nonmalignant cells. Although showing induced reprogramming in both Philadelphia chromosome-positive (Ph+) and Ph− cases, the authors concentrate on Ph+ leukemias, proposing reprogramming to be a possible therapeutic modality for this high-risk group of B-ALLs. Although the findings are highly interesting and relevant, we would like to raise several points of concern.