IL18 and plasma cell myeloma: Indeed, it was shown that after the first round of αPD-L1 immunotherapy, IL-18 levels increase in sera of patients with multiple myeloma, non-small cell lung cancer, renal cell carcinoma and melanoma, which is linked to a reactivation and cytotoxicity of antitumor effector cells, namely IFN-γ production [138,139].