Soluble PD-L1: From Immune Evasion to Cancer Therapy.

Immunotherapy has emerged as a promising approach to cancer treatment, but only a small percentage of cancer patients benefit from it. To enhance therapeutic outcomes, it is essential to understand factors influencing immune response and tumor progression. Soluble PD-L1 (sPD-L1) has been identified as an essential element in immune regulation, with potential implications in cancer biology and treatment. This manuscript explores the sources and mechanisms of sPD-L1 production, its role in immune evasion and tumor progression, and its clinical significance. Elevated sPD-L1 levels have been linked to disease severity, survival, and treatment response in various malignancies, and as a consequence, strategies for combinatorial targeting of sPD-L1 with other immunotherapies are considered. Further studies are needed to understand sPD-L1 dynamics and to clarify the mechanisms of sPD-L1-mediated immunosuppression and its therapeutic implications.