CD84 and acute myeloid leukemia: We used the lentiviral vector–based shRNA system to knock down the expression of CD84 (shCD84-1 and shCD84-2) (Figure 2A) and demonstrated that CD84 downregulation caused a statistically significant inhibition of cell growth (Figure 2B) as well as induction of apoptosis in AML cell lines (Supplemental Figure 3, A and B).