BRAF and neoplasm: Raf is a major proliferative and antiapoptotic effector, and it was recently shown that BRAF, one of the Raf kinases, is frequently activated by mutation in human tumours, particularly melanomas (∼70%) and colorectal tumours (∼15%) (Davies et al, 2002; Rajagopalan et al, 2002; Yuen et al, 2002).