KLRG1 and glioblastoma: RT + Conc.IT induced a clear shift in the abundance of these populations, with KLRG1intCD103int Tregs (population 2; KLRG1+ Tregs) being the most predominant subset in RT-treated glioblastoma and a CD103+KLRG1− Treg subpopulation (population 1; CD103+ Tregs) being most abundant in RT + Conc.IT-treated glioblastoma (Fig. 4c,d).