However, we recommend that patients with suspected gastric GIST smaller than 20 mm should be referred for resection if any of the following is present: 1) nodule with irregular margin, signs of ulceration or bleeding, or an increase in size during follow-up; 2) presence of cystic change, necrosis, heterogeneous echogenecity, or lobulation, or if there is poor patient compliance with follow-up; or 3) diagnostic confirmation of GIST through fine-needle aspiration biopsy (FNAB) or if it is a KIT-positive tumor. The gene discussed is KIT; the disease is neoplasm.