PSMB5 and neoplasm: Moreover, the tumor cell subpopulations expressing the highest level of PSMB5 (GP3-B1) are different from the ones of MYC, OTX2 or CRX (GP3-B2 for MYC, GP3-C2 for OTX2 and CRX), further supporting the involvement of unidentified SE-associated TFs in regulating PSMB5 transcription in G3-MB (Fig.S4).