CD274 and neoplasm: 10, 11. In the antitumor immunity, celecoxib treatment can promote the CD8+ CTL infiltration and reduce the FOXP3+ Treg recruitment in tumor tissues by IDO downregulation 12, 13. Moreover, celecoxib therapy can attenuate the M1 to M2 polarization and the PD‐L1 expression of TAMs 14, 15.