CTLA4 and neoplasm: Exhausted CD8+ T cells can express multiple inhibitory receptors such as programmed death 1 (PD-1), cytotoxic T-lymphocyte associated protein 4 (CTLA-4), TIM-3 (also known as HAVCR2), lymphocyte-activating 3 (LAG3) and T cell immunoreceptor with Ig and ITIM domains (TIGIT), which serve as targets for immune checkpoint blockade.[36], [37] Improved understanding of their hierarchical expression by tumour sampling could direct personalised ICI selection in the future.