TP53 and glioma: The most commonly used mouse model of glioma, GL261, was established on the C57BL/6 background 50 years ago by chemical mutagenesis and was initially described as resembling ependymoblastoma by histology.18 The SB28 mouse model of invasive glioma was developed in 2014 through simultaneous suppression of p53, overexpression of Pdgfb and hyperactive ERK signaling through NRASG12D, also on the C57BL/6 background.19 We analyzed bulk RNAseq datasets from in vivo orthotopic (intracerebral) SB28 and GL261 tumors and compared these to a reference cohort of human primary brain tumors.