In B16 melanoma tumors, dual LAG-3 and PD-1 depletion on TILs diminished tumor-induced tolerance and yielded higher responses compared to single-checkpoint-deficient mice, eliminating 80% of tumors (vs. 40% elimination in PDCD1−/−, and no tumor growth control in wild-type and LAG-3−/−mice). The gene discussed is PDCD1; the disease is melanoma.