TP53 and central nervous system cancer: However, when ACVR1 R206H, G328V, or G328E was co-injected along with HA-epitope and FLAG-epitope tagged H3.1K27M and Cre to induce p53 loss, mice were able to generate glioma-like lesions in vivo (4/10 = 40%, 4/13 = 31%, and 1/8 = 13%) (Fig. 2 and Supplementary Table 1).