XI-101, as novel small molecule ligand of hnRNPA2B1, disruptes the binding of hnRNPA2B1 to the MDMX promoter and UTR and inhibits MDMX transcription, upregulates of p53, enhances expression of proapoptotic genes as downstream of p53, and ultimately induces apoptosis of gastric cancer cells. This evidence concerns the gene MDM4 and gastric cancer.