A. SCC9, SCC25, CAL27, and CAL33 were treated with increasing concentrations of GSK126 or EPZ6348 (1 nM-100 μM) for 72 hours to test assess impact on cell viability. B. Human HNSCC cells were treated with GSK126 (10 μM), EPZ6438 (10 μM), or DMSO as control for 72 hours. IFNγ was added in the last 24 hours of drug incubation for all assays shown. HLA cell surface protein levels were measured by flow cytometry. The data are representative of 2 independent experiments. C. B2M and CXCL10 mRNA expression levels were quantified by qRT-PCR. Relative mRNA levels were normalized to GAPDH. *P<0.05, **P<0.01, ***P<0.001. Significance was calculated by one-way ANOVA. Data are shown as Mean± SD.