To validate the above hypothesis, the PD-L1 overexpression vectors were successfully transfected into CR-GC cells (P < 0.05, Fig. 4h, i), and the results showed that upregulation of PD-L1 promoted the stemness signatures (SOX2, OCT4 and Nanog) expressions to improve CSCs properties in DB-treated CR-GC cells (P < 0.05, Fig. 4j–m). This evidence concerns the gene SOX2 and gastric cancer.