In the version of this Article originally published, in ref. 34 the first author's name was spelled incorrectly. The correct reference is: Rodón, L. et al. Active CREB1 promotes a malignant TGFβ2 autocrine loop in glioblastoma. Cancer Discov. 10, 1230-1241 (2014). This has now been amended in all online versions of the Article.