BCL9L and colorectal cancer: Vertebrates encode two orthologs of each (Pygo1 and Pygo2, BCL9 and B9L/BCL9-2), which are required for efficient TCF-dependent transcription in Wnt-dependent tissue contexts (Gu et al., 2009; Li et al., 2007; Schwab et al., 2007; Song et al., 2007) and in human colorectal cancer cells with activated β-catenin (Adachi et al., 2004; Brembeck et al., 2004; de la Roche et al., 2008; Thompson et al., 2002).