The expression levels of EV‐derived lncRNA‐GC1 were evaluated as a biomarker for predicting and monitoring immunotherapeutic outcomes in GC patients across four cohorts, including 84 patients in a retrospective training phase, 124 and 131 patients in retrospective validation cohorts, and 80 patients in a prospective validation phase.[121] Patients with lower EV‐derived lncRNA‐GC1 levels demonstrated better PFS and OS, with median PFS ranging from 9.7 to 22.3 months and OS from 12.7 to 26.5 months, independent of PD‐L1 expression or CD8+ T cell infiltration. The gene discussed is CD274; the disease is gastric cancer.