APC and cancer: Among all PP2A forms, the PP2A B56 family plays a critical role in cancer biology, and is involved in dephosphorylation and regulation of a number of critical oncoproteins and tumor suppressors in the cell, including p53, myc and Wnt pathway components including β-catenin and APC (Arnold and Sears, 2006; Gao et al., 2002; Li et al., 2007; Li et al., 2001; Seeling et al., 1999; Virshup and Shenolikar, 2009).