IDH1 and oligodendroglioma: In contrast, luciferase-modified oligodendroglioma PDCs (SF10417 PDC-LUC GNS) yielded infiltrative tumors in 4 of 9 mice and the tumors exhibited oligodendroglioma histologic features (Figure 4D and E) and maintained IDH1 R132H expression as measured by IHC on formalin-fixed, paraffin-embedded xenograft tissue (Figure 4F).