P Laird, USA, explained the clinical use of DNA methylation markers for early detection and prediction of chemoresistance, and showed that CpG island methylator phenotype-high (CIMP-H) tumours encompass most BRAF mutant tumours and that CIMP-H is responsible for most sporadic microsatellite instabiligy (MSI)-high tumours by MLH-1 promotor methylation. The gene discussed is BRAF; the disease is neoplasm.