CD274 and lip and oral cavity carcinoma: In an OSCC model system of adoptive T cell therapy immune escape, using UM-SCC-1 and UM-SCC-47 oral cancer cell lines with varying admixtures of HLA-expressing and HLA-nul tumor cells, the addition of PD-L1 t-haNK in vitro was able to salvage response and prevent clonal outgrowth of escape variant tumor cells [167].