Fix PTEN: EXP>1 test for multiple studies
Fix PTEN: EXP>1 test for multiple studies

Copied from
https://github.com/cBioPortal/cbioportal-frontend/pull/1110

Former-commit-id: 65b59ce80d0d648ccf6723eb5ee1b755ab820580
cBioPortal/cbioportal-frontend,alisman/cbioportal-frontend,alisman/cbioportal-frontend,cBioPortal/cbioportal-frontend,alisman/cbioportal-frontend,alisman/cbioportal-frontend,cBioPortal/cbioportal-frontend,cBioPortal/cbioportal-frontend,cBioPortal/cbioportal-frontend,cBioPortal/cbioportal-frontend,alisman/cbioportal-frontend,alisman/cbioportal-frontend