The antitumor efficacy of anti-BTLA mAbs has been shown [212,213]. In the blockade of BTLA, an increase in the proliferation and expansion of NY-ESO-1-specific CD8+ T-cells was observed, and an increased efficiency of the use of mAbs targeting BTLA in combination with anti-PD-1 and anti-Tim-3 in melanoma was shown [214]. An increase in median OS [215], as well as the enhancing T-cell proliferation and cytokine production, was observed with the combination of anti-BTLA and anti-PD-1 therapies [216]. The gene discussed is PDCD1; the disease is melanoma.