CD274 and glioblastoma: However, the mean fluorescent intensity (MFI) between the two groups was significantly different, indicating the levels of PDL1 proteins on the non-CD45 cells was increased in GBM patient samples compared with normal donor brain, MFI of 476 in ND versus MFI of 1014 in GBM, p = 0.0016, (Figure 3D).