APC and colorectal cancer: Importantly, embryonic stem cells derived from Apc1638T/1638T mice develop hallmarks of CIN (Fodde et al., 2001), and overexpression of truncated APC lacking the C-terminal domains in chromosomally stable colorectal cancer cells leads to mitotic defects, including errors in kinetochore attachment and alignment of chromosomes (Green and Kaplan, 2003; Tighe et al., 2004).