The addition of Hist1h3bK27M/+;Pik3cafloxH1047R/+ mutations to ACVR1floxG328V/+; Olig2Cre cells induced tumors consistent with high-grade diffuse gliomas, suggesting that OPCs could be the tumorigenic origin cell of DMG tumors.22 Another study by Anderson et al. confirmed the tumorigenic potential of Olig2 + cells by showing that DMG cells with Olig2 expression formed Olig2 + brainstem gliomas with 100% penetrance in xenograft models. The gene discussed is OLIG2; the disease is brain stem glioma.