The present invention provides, in certain embodiments, isolated peptides and pharmaceutical compositions comprising isolated peptides that bind to retinoblastoma binding protein 4 RBBp4 such that, the binding blocks the SALL4-RBBp4 interaction. Methods of inhibiting binding of SALL4 with RBBp4 and methods for treating a subject having a disorder mediated by a dysregulation of SALL4 are also provided.