FGF4 and cancer: Amplification of the 11q13 locus, where CTTN resides, is the most frequent amplification event in HNSCC and may be driven by a set of genes that could cooperatively provide growth or metastatic advantage to cancer cells including CCND1, FGF4, FGF3, SHANK2, and PAK1 (see Huang et al, 2002, 2006 and Gibcus et al, 2007).