CD274 and non-small cell lung carcinoma: Although validation in clinical trial results remains needed, authors of a meta-analysis suggested that pre-treatment soluble PD-L1 and exosomal PD-L1 act as unfavorable prognostic factors to patients with NSCLC undergoing ICI therapy, and that the dynamic upregulation of post-treatment exosomal PD-L1 levels indicates a favorable prognosis [67].