Seo et al. identified TOX and TOX2 upregulation in PD-1+TlM-3hi exhausted CAR-T cells in a B16–human CD19 (hCD19) melanoma model, whereas double KO of TOX and TOX2 revitalized the exhaustion process and restored effector functions, including elevated IFN-γ and TNF-α production (33). The gene discussed is TOX; the disease is melanoma.