We also determined the in vivo efficacy of VX-970 in mice with established tumours derived from a tumour cell line with naturally occurring ARID1A mutations (TOV21G, ARID1A p.548fs/p.756fs). In in vitro studies, we found that the TOV21G human OCCC cell line was more sensitive to both VE-821 and VX-970 than the ARID1A wild-type OCCC cell line RMG1