She was diagnosed with metastatic gallbladder adenocarcinoma with low tumor mutation burden that harbored ARID1A deletion (exons 6–20) and rearrangement, CDKN2A/B and MTAP homozygous deletion, PIK3R1 N564D, and NBN P81fs*23 in mutational analysis….The patient was administered MRTX1719 100 mg q.d. p.o. on a 21-day cycle....The patient had an initially increasing tumor marker that later decreased (Supplementary Fig. S7B), and a gradual decrease in the gallbladder lesion that achieved a RECIST-defined partial response with a 43% reduction at cycle 8 day 12 and was confirmed at cycle 10 day 12 (Fig. 6).