The present invention relates to an inhibitor of MELK and/or ROR2, preferably for use in the treatment of diffuse intrinsic pontine glioma (DIPG), wherein said DIPGis preferably characterized by Overexpression of MELK and/or Overexpression of ROR2. The inhibitor may be combined with a P-glycoprotein inhibitor, an Abcb1 a inhibitor, Abcb1 b inhibitor, mannitol, or an Abcg2 inhibitor.