In a mouse model of CAC, α1HMZ mice exhibited decreased tumor load, suggesting that expression of HNF4α1 from the P2 promoter in the proliferative compartment may protect against tumorigenesis, consistent with studies showing a loss of P1-HNF4α in human colon cancer (Chellappa et al., 2012; Tanaka et al., 2006; Oshima et al., 2007), a tumor suppressive role for P1-HNF4α in mouse liver (Hatziapostolou et al., 2011; Walesky et al., 2013b) and our recent colon cancer xenograft studies showing that ectopic expression of P1-HNF4α reduces tumor growth (Vuong et al., 2015). The gene discussed is HNF4A; the disease is malignant colon neoplasm.