passages.id: split_5_test_1027_passage
passages.type: progene_text
passages.text: A proportion of APC wild - type colon carcinomas and melanomas also contains constitutive nuclear Tcf-4 / beta-catenin complexes as a result of dominant mutations in the N terminus of beta-catenin that render it insensitive to downregulation by APC , GSK3 beta , and Axin / Conductin .