Based on this solved structure, we next conducted a series of structural modifications to get compounds 13 -20 to further explore the interactions with this benzonitrile binding subpocket. As shown in From the cocrystal structure of NSD3-PWWP1 in complex with BI-9321, we can learn that the benzylamine group interacts with Glu318 residue by a hydrogen bond and this residue is conserved in the PWWP1 domain of NSD2. We synthesized and tested compounds bearing different hydrogen bond groups as the replacement of the benzylamine group. As shown in Table , almost all these compounds lost activity against NSD2 by showing IC 50 values greater than 20 μM. Notably, compounds 24