Blockade of the PD-1:PD-L1 axis may counteract this adaptive resistance, restoring APC function, and enhancing T-cell-targeting of tumors; indeed, PD-L1 expression by infiltrating myeloid, rather than tumor cells was predictive of clinical response to PD-1 pathway blockade in a recently reported phase I study (78). Here, CD274 is linked to neoplasm.