CD8A and neoplasm: As PD-1 and TIM-3 are co-expressed in tumor-containing animal models, TIM-3+ PD-1+ CD8+ TILs are perhaps the most prevalent subgroup and demonstrate more exhausted characteristics than both TIM-3- PD-1- and TIM-3+ PD-1+ CD8+ TILs, which fail to synthesize TNF-α, IFN-γ, and IL-2.124