PDCD1 and cancer: In addition, evolving ICs such as T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), lymphocyte activation gene 3 (LAG-3), T cell immunoreceptor with Ig and ITIM domains (TIGIT) and inducible T cell costimulatory (ICOS) among others, are relatively in adolescent phase in their clinical translation as part of cancer immunotherapy regimens, compared to established ICs; programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4).