Bocanegra Gondán, Ana IsabelBlanco, EsterFernández Hinojal, GonzaloChocarro de Erauso, LuisaZuazo Ibarra, Miren2021-02-042021-02-0420201422-0067 (Electronic)10.3390/ijms21165918https://academica-e.unavarra.es/handle/2454/39151The use of monoclonal antibodies targeting PD-1/PD-L1 axis completely changed anticancer treatment strategies. However, despite the significant improvement in overall survival and progression-free survival of patients undergoing these immunotherapy treatments, the only clinically accepted biomarker with some prediction capabilities for the outcome of the treatment is PD-L1 expression in tumor biopsies. Nevertheless, even when having PD-L1-positive tumors, numerous patients do not respond to these treatments. Considering the high cost of these therapies and the risk of immune-related adverse events during therapy, it is necessary to identify additional biomarkers that would facilitate stratifying patients in potential responders and non-responders before the start of immunotherapies. Here, we review the utility of PD-L1 expression not only in tumor cells but in immune system cells and their influence on the antitumor activity of immune cell subsets.17 p.application/pdfeng© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.PD-L1ImmunotherapyImmuneCheckpoint inhibitionSystemic myeloid subsetsLiquid biopsyBiomarkersinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess