CD274 and cancer: Cancers have been categorized into four different tumor microenvironments based on the presence of TILs and PD-L1 expression, and of these, Type I tumors (PD-L1+, TILs+) are the most likely to benefit from anti-PD-1/L1 blockade, as they are “warm tumors” with increasing intratumor T cells28,29.