CD274 and head and neck squamous cell carcinoma: UM-SCC-49, which was derived from an aggressive tongue HNSCC, was selected as a model based on its ability to upregulate PDL1 in response to IFNγ compared to other HNSCC cell lines (data not shown), previously published exome sequencing demonstrating that genes from the established IFNγ signaling pathway are not mutated in this cell line, and growth characteristics amenable to scaling cell culture for high throughput screening [12].