IDH1 and astrocytoma (excluding glioblastoma): However, while 20 to 40% of the tumour cells from wild-type IDH1/2 astrocytomas showed strong staining for p-AKTT308, the upstream activator of mTORC1, less than 2% of IDH1R132H-mutated astrocytomas stained positively for p-AKTT308 (Fig. 4i).