Although CRC-associated APC truncations were less able to stimulate β-catenin poly-ubiquitylation, APC ΔCID behaved identically to wild-type APC (Figures 4A, 4B, S5A, and S5B), suggesting that the essential role of the CID region in cells (Choi et al., 2013; Kohler et al., 2009; Liu et al., 2006; Novellasdemunt et al., 2017; Roberts et al., 2011) is mediated by other factors not present in our in vitro system. The gene discussed is APC; the disease is colorectal carcinoma.