PROM1 and neoplasm: To investigate PTPRZ1 expression pattern in GBMs, we co-immunostained PTRPZ1 and several GSC markers in frozen GBM specimens and found a preferential expression of PTPRZ1 in tumour cells expressing GSC markers SOX2, OLIG2 and CD133 (Fig. 3e–g and Supplementary Fig. 4e).