To determine if PML disruptions are indeed specific to H3.3 mutations, we compared H3.3 K27M with four H3.1 K27M mutated patient-derived glioma cell lines SU_DIPG_36 (#1), ICR_B184_2D (#2), SU_DIPG_33 (#3) and SU_DIPG_4 (#4). The gene discussed is PML; the disease is glioma.