Gene by gene functional analyses have revealed that cyclin D1 (Opitz et al, 2001; Nelsen et al, 2005), FADD (Alappat et al, 2003; Chen et al, 2005) and cortactin (van Rossum et al, 2003; Luo et al, 2006) are potentially able to enhance cancer development. This evidence concerns the gene CTTN and cancer.