SPDL1 and neoplasm: In this study, we measured the pretreatment serum sPD‐L1 level in patients with advanced NSCLC who received anti‐PD‐1 antibody and assessed the relationship between the serum sPD‐L1 level and the clinical characteristics, PD‐L1 expression on tumor cells, the response to anti‐PD‐1 antibody, and patient outcome.