We found that as early as the first week after tumor implantation, there were infiltrating CD45+ immune cells, mainly in the tumor-side (ipsilateral) right hemisphere (RH), compared with the contralateral left hemisphere (LH), and these infiltrates continued to increase over time following GBM engraftment (Figure 1D, Supplementary Figure S1C). Here, PTPRC is linked to glioblastoma.