CD19 and gastric cancer: It was found that T cells co-expressing iKP CAR and CD19 CAR could effectively differentiate between HLA-naïve Daudi cell lines and HLA-expressing normal B cells, while cells of the gastric cancer cell line MGC803, which expresses low levels of HLA, were killed in high numbers, while the effect was markedly reduced in gastric cancer cells expressing high levels of HLA.