We also found that PD-1H expression was higher in monocytic leukemia cell lines (THP1, U937, MOLM14) than in leukemia cell lines containing RUNX1-RUNX1T1 (Kasumi1) and PML-RARα (HL-60, NB40) (Supplemental Figure 5). This evidence concerns the gene RARA and monocytic leukemia.