Our study suggests that the expression of MDM2, CDK4 and p53 (TP53) and the mutational status of TP53 may be useful to identify patients with high risk localized GIST who carry an increased recurrence risk and may benefit from a prolonged adjuvant treatment with imatinib although the TP53 mutation frequency is very low in treatment naïve, high risk GIST. The gene discussed is CDK4; the disease is gastrointestinal stromal tumor.