HDAC9 and acute lymphoblastic leukemia: For example, MDM2 inhibition was shown to synergize with: 1) MAPK pathway inhibition in acute myeloid leukemia [AML] and melanoma cells [28-31], 2) PI3K pathway antagonism in AML and acute lymphoblastic leukemia cells [32, 33], 3) HDAC inhibition in AML, lung, and ovarian cells [34, 35], 4) dual Bcl-2/Bcl-xL inhibition in AML cells [36], 5) BCR-ABL kinase inhibition in Philadelphia chromosome-positive chronic myelogenous leukemia and acute lymphoblastic leukemia cells [37], and 6) dasatinib in primary B chronic lymphocytic leukemia cells [38].