Micromanagement of drug-resistant advanced gastrointestinal stromal tumors: regorafenib—new ammunition in battling exon 17 mutations

Gastrointestinal stromal tumors (GIST) are the most common gastrointestinal (GI) mesenchymal tumors originating from pluripotent precursor mesenchymal cells that normally differentiate into the interstitial cells of Cajal.