In addition to tumour behaviour we also considered promoter methylation as a predictor of disease-specific mortality: In this case, HOXA9 promoter methylation demonstrated 57.1% specificity and a 70.6% negative predictive value (NPV) for disease-specific mortality, whilst ISL1 methylation suggested 57.1% and 60.0% for these outcome measures. The gene discussed is ISL1; the disease is neoplasm.