CCND1 and malignant colon neoplasm: Previous works provided evidences that mutant β-catenin produces high levels of cyclin D1 messenger RNA and protein constitutively in colon cancer cells.8 Z86 reduced the expression of cyclin D1 at both the mRNA and protein levels in a dose- and time-dependent manner in HCT116 and other colon cells (Figures 2b and c).