JAK2 and Aagenaes syndrome: We and others demonstrated previously that type I JAK2is can kill JAK2V617F-driven MPNs (Supplemental Fig. S1A,B; Geron et al. 2008; Wernig et al. 2008), TEL-JAK2-driven T-cell ALLs (T-ALLs) (Waibel et al. 2013), JAK2-amplified classical Hodgkin lymphomas (cHLs), and primary mediastinal large B-cell lymphomas (Hao et al. 2014).