ACVR1 and diffuse intrinsic pontine glioma: Analyses of tumor evolution in DIPG patients have indicated that H3F3A, HIST1H3B, and ACVR1 mutations occur very early during tumorigenesis, and are positively selected during tumor progression (Hoffman et al., 2016, Nikbakht et al., 2016, Vinci et al., 2018).