CTLA4 and cancer: The efficacy of whole-cell vaccines can be further boosted by introducing various cytokines, co-stimulatory molecules, pattern recognition receptor agonists, checkpoint blockers, etc. Blockade of checkpoint, namely, co-inhibitory molecules, such as CTLA-4, PD-1, LAG-3 and TIM-3, have shown great prospect in cancer treatment in both preclinical and clinical researches.