BMP4 and glioma: Interestingly, while this manuscript was in preparation, BMP4, a well-known inducer of GSC differentiation, was shown to promote senescence in glioma-initiating cells and also sensitized them to navitoclax [26], suggesting that the promotion of senescence coupled with increased sensitivity to navitoclax is not unique to CEP-1347, but may be shared, albeit not necessarily, by inducers of GSC differentiation.