Overall, we show that LRRC4 exerts its inhibitory function on CD4+CCR4+ T cells in the GBM microenvironment via the PDPK1/IKKβ/NF-κB/cytokine pathway, and our findings provide new insights into PDPK1/NF-κB signaling. Here, PDPK1 is linked to glioblastoma.