BRAF and neoplasm: Moreover, a significant incidence of BRAFV600E mutation has been found in undifferentiated thyroid cancers, suggesting that ATC may arise from more typical forms of PTC and that BRAF signalling may be functionally relevant in tumor progression (Nikiforova et al. 2003; Begum et al. 2004; Soares et al. 2004; Trovisco et al. 2004; Santarpia et al. 2008).