Infiltration of CD8+ and CD4+ T cells but not FoxP3+ Treg cells, as observed in our Cx3cr1‐Rheb1Δ/Δ tumours, correlates with long‐term survival in GBM patients (Heimberger et al, 2008; Yang et al, 2010; Abedalthagafi et al, 2018), hence providing the rationale for immunotherapies aimed at modifying the infiltration or immune reactivity of the T‐cell population, such as drugs targeting inhibitory checkpoints. The gene discussed is CD4; the disease is glioblastoma.