Moreover, Pfister et al. identified an increased number of exhausted, activated CD8+PD1+ T cells in mice fed a CD-HFD; deletion of these cells in mice suffering from MASH prevented HCC incidence and provided additional evidence for the pro-tumorigenic role of CD8+ T cells (Pfister et al., 2021). The gene discussed is PDCD1; the disease is hepatocellular carcinoma.