In order to verify whether miR-9 affects biological functions such as sharp increase and apoptosis of AML cells by inhibiting Hippo/YAP signaling pathway, after transfection of miR-9 mimic, NC mimic, miR-9 inhibitor, and NC inhibitor, the expression levels of the corresponding proteins MAT1, LATS1, LATS2, and YAP in the Hippo/YAP signaling pathway were tested. Here, YAP1 is linked to acute myeloid leukemia.