The increase may be triggered by previous immunotherapy (as in this work) or circulating inflammatory mediators: Interferon-y, as a pivotal inflammatory cytokine, has been identified at the interface between PD-L1 bearing tumor cells and tumor infiltrating leukocytes and is a potent inducer of sPD-L1 expression both in vitro and in vivo [12, 16]. This evidence concerns the gene SPDL1 and neoplasm.