Successful transduction of PD-L1 in leukemia cells was confirmed by flow cytometry, which showed low PD-L1 expression in parental Raji, CA46, and K562 cells, and moderate to high PD-L1 expression in PDL1-Raji, PDL1-CA46, and PDL1-K562 cells (Figure 5B). This evidence concerns the gene CD274 and leukemia.