Given its suboptimalphysicochemical properties, NAH-C3-GPKK is unlikely to enter cells.Recently, a bisubstrate inhibitor (KMI169,Figure S1A) was shown by us to specifically blockKMT9 enzymatic activity with cellular activity, providing a proofof concept that pharmacologically targeting KMT9 blocks cancer cellproliferation. So far, no other SAR studieshave been published on KMT9. This evidence concerns the gene HEMK2 and cancer.