H3C3 and diffuse intrinsic pontine glioma: In addition, HIST1H3B or HIST1H3C, one of the 13 genes encoding canonical histone H3.1/H3.2, is also mutated, resulting in the same K to M change in a small fraction of DIPG tumors (Castel et al., 2015; Fontebasso et al., 2014; Solomon et al., 2016).