SEMA4D and precursor B-cell acute lymphoblastic leukemia: Considering that Sema4D expression is only highly expressed in BMMCs of AML and B-ALL (Figure 2(b)), the correlation analysis was performed on Sema4D expression in BMMCs of AML and B-ALL and the soluble Sema4D level in serum, and no correlation was found (Figure 2(d)).