While the combination of LSD1 knockdown and SAHA treatment has previously been reported to downregulate BCL-2 expression and to increase BAX levels, the functional relevance of these changes for the combination-induced cell death has, however, remained obscure.36 Furthermore, in the present study we demonstrate synergistic tumor cell death using specific LSD1 inhibitors such as GSK690 and Ex917, whereas most previous combination studies were conducted with Tranylcypromine or Pargyline,32, 33, 35, 36 which are unspecific LSD1 inhibitors that mainly target MAO-A and/or MAO-B.26 Here, MAOB is linked to neoplasm.