PDCD1 and gastric cancer: Retroviral transduction with DTCR (PD1-DAP10/NKG2D) can significantly increase the expression of NKG2D (an activating receptor on the surface of NK cells) on the surface of NK92 cells, thus enhancing cytotoxicity against GC cells SGC-7901, and DTCR-NK92 cells showed strong anti-tumor activity in the GC mouse model (185).