MSI2 and acute promyelocytic leukemia: Accordingly, we selected common downstream proteins regulated by Snail1 and identified that the expression level of MSI2 was positively correlated with that of MMP2 in AML patients (Fig. 4E), with the findings that MMP2 was overexpressed in AML (Additional file 1: Fig. S6C, D) and had a poor prognosis in AML patients excluding acute promyelocytic leukemia (Fig. 4F).