SPDL1 and neoplasm: In addition, elevated levels of soluble PD-L1 (sPD-L1) were produced and released by activated mature dendritic cells (mDC), and sPD-L1 has been identified in cancer patients and was associated with increased cancer-related death; tumor-derived or mDC-derived sPD-L1 was active, inducing apoptosis in T cells [95,96].