Fig 1: WP1066 treatment leads to downregulation of p-STAT3 and PD-L1. (A) Flow analysis and quantitative analysis of the ability to suppress T cells proliferation when M-MDSCs were treated with 0, 5 and 10 µM STAT3 inhibitor WP1066 for 24 h. (B) p-SATA3 positive cells and (C) PD-L1 positive cells were determined by flow cytometry and quantitative analysis. (D) Secretion of IFN-γ on treated M-MDSCs by ELISA. *P<0.05, **P<0.001, ***P<0.0001. p-, phosphorylated; PD-L, programmed death ligand; M-MDSCs monocytic myeloid-derived suppressor cells.