CD274 and neoplasm: Bearing in mind the robust advances made with the development of programmed cell death ligand-1 (PD-L1) and programmed cell death-1 receptor (PD-1) inhibitors in a number of solid malignancies, immune oncology remains an essential part of the current research activities in PCa, despite the fact that PCa is considered a non-immunoreactive and a “cold” tumor with an immunosuppressive tumor microenvironment (TME) and low infiltration burden of T cells.