WM39 cells were stably transduced with a lentiviral shRNA specific for STING (sh-STING) or non-target shRNA (sh-control). (A) Immunoblot analysis of STING expression in WM39, sh-control, and sh-STING cells. Whole-cell lysate (20 μg) was used and β-actin was analyzed as a loading control. (B) Immunoblot analysis of p-IRF, total IRF3, and β-actin in WM39, sh-control and sh-STING cells after stimulation with 2’3’-cGAMP or lipofectamine. (C) Induction of CXCL10 and (D) IFN-β in WM39, sh-control and sh-STING cells after stimulation with 2’3’-cGAMP or lipofectamine. (E) Representative histograms of HLA-A.B.C expression on indicated cells with or without 2’3’-cGAMP stimulation. (F) Mean fluorescence intensity (MFI) of HLA-A.B.C on indicated cells. Data are presented as mean ± SD of three biological replicates. P-values were calculated by one-way ANOVA (**P < 0.01, ***P < 0.001, ****P < 0.0001).