Tumours in the gastric location with spindle cell morphology and high mitosis may be tested for KIT exon 11 while gastric tumours with low mitosis, epithelioid morphology and low cellular atypia may be tested initially for PDGFRA exon 18 in the first phase, or if feasible, gastric GISTs should be first tested for KIT exon 11 followed by PDGFRA exon 18. The gene discussed is KIT; the disease is neoplasm.