RT-PCR results also showed that the gene expression of BMP2 in the B-ALL group was significantly higher than that in the control group (p < 0.001, Figure 2I), and it was significantly negatively correlated with the gene expression of miR-539-5p (p < 0.05, Figure 2J). The gene discussed is BMP2; the disease is precursor B-cell acute lymphoblastic leukemia.