For the first time, patients with advanced gastrointestinal (GI) stromal tumours (GISTs) have had an effective response to systemic therapy. When treated with the signal transduction inhibitor STI 571, 59% of patients with this rare solid tumour had a partial response and 26% had disease stabilisation, representing an overall tumour control rate of 85%. These phase II data were reported at the 37th Annual Meeting of the American Society of Clinical Oncology (ASCO) [San Francisco, US; May 2001] along with data from a smaller phase I trial which also showed an improvement in most patients treated with the drug. STI 571 recently hit the headlines following extremely positive results in patients with chronic myeloid leukaemia (CML)*and was approved in the US just days before this year's ASCO meeting for the treatment of patients with CML in blast crisis, accelerated phase or chronic phase in whom treatment with interferon has failed.**