New investigations have reported some negative regulators of T cell activation as adjuvant cancer drugs, e.g., lymphocyte activation gene 3 (LAG3), T cell immunoglobulin 3 (TIM3), V-domain immunoglobulin suppressor of T cell activation (VISTA), B7-H3 and T cell immunoreceptor with immunoglobulin, and immunoreceptor tyrosine-based inhibitory motif domains (TIGIT) [99,100,101]. Here, LAG3 is linked to cancer.