CTLA4 and neoplasm: With higher expression levels of CTLA-4, PD-1, CD39, and IFN-γ receptors than Tim-3- Tregs, Tim-3+ Tregs accumulate earlier than exhausted CD8+ T cells in the tumor tissue and promote tumor growth by sustaining dysfunctional CD8+ T cell development but inhibiting naïve T cell proliferation4, 86.