HLA-DPA1 and neoplasm: In a tumor killing assay, however, only the 4367_TCR-2-expressed T cells significantly (p = 0.004) suppressed the growth of the HTB-114 tumor cells, gene-engineered to co-express the DPA1*01:03/DPB1*04:01 and the mutant PIK3CAN345K protein (Fig. 2I).