AUTHOR=Chen Wei , Wei Qiance , Xiao Tong , Lai Jinghan , Huang Mengmeng , Ma Yueran , Zhang Lili , Xue Wenxin , Liu Shui , Sun Lichaoyue , Li Wenshu , Bu Zhijun , Lou Junge , Liu Zhaolan TITLE=Evaluating the efficacy and safety of immune checkpoint inhibitors in first and second-line treatments for recurrent and metastatic head and neck squamous cell carcinoma: a systematic review and network meta-analysis of RCTs with a focus on PD-L1 expression JOURNAL=Frontiers in Immunology VOLUME=16 YEAR=2025 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2025.1508885 DOI=10.3389/fimmu.2025.1508885 ISSN=1664-3224