,18 Previous research has shown that therapeutic blockade of PD-1/PD-L1 signaling significantly increases survival time of immunocompetent mice inoculated systemically with syngeneic murine K7M2 osteosarcoma tumor cells, which mostly become localized within metastatic lung lesions after systemic intravenous (i.v.)infusion.19 The gene discussed is CD274; the disease is osteosarcoma.