SPDL1 and cancer: While there are some conflicting findings, which may be impacted by heterogeneity of the patient populations evaluated, the type of material and assays utilized to measure sPD-L1, and variation in the cut points used in which to stratify patients into groups, the vast majority of these studies indicate that lower levels of sPD-L1, prior to initiating ICI, can identify patients with a variety of cancers with improved clinical responses following ICI.