Whereas, for the ERK1/2 pathway, specific somatic mutations in BRAF or NRAS (such as BRAFV600E or NRASQ61K/L) cause ERK1/2 pathway activation and drive tumour cell proliferation, survival and motility, somatic mutations in ERK5 signalling pathway components are rare and none have been detected with high frequency. The gene discussed is BRAF; the disease is neoplasm.