Chemokine C‐C motif ligand 21 (CCL21) stabilized programmed death‐ligand 1 (PD‐L1) through the AKT‐glycogen synthase kinase‐3β (GSK‐3β) signaling pathway. A, Western blot analysis of PD‐L1 abundance in MIA‐PaCa‐2 and SW1990 cells treated with 80 μΜ cycloheximide (CHX) for 0, 4, 8, 12, or 16 h after CCL21 stimulation (right) or not (left). B, Western blot analysis of AKT‐GSK‐3β signaling pathway changes of starved cells treated with serum‐free medium contained CCL21 (50 ng/mL) for 0, 15, 30, 60, and 120 min. C, Western blot analysis of the AKT‐GSK‐3β signaling pathway changes of starved cells pretreated with DMSO, AKT inhibitor (LY294002, 20 μmol/L) or anti‐CC‐chemokine receptor 7 (CCR7, 10 µg/mL) for 2 h, and then treated with CCL21 (50 ng/mL) or PBS for an additional 2 h. D, Western blot analysis of PD‐L1 expression in starved cells pretreated with DMSO, LY29400,2 or anti‐CCR7 for 2 h, and then treated with CCL21 (50 ng/mL) or PBS for an additional 48 h. E, Coimmunoprecipitation assays in MIA‐PaCa‐2 and SW1990 cells transfected with indicated plasmids