MUC5AC and colorectal cancer: Other mucin changes in colorectal cancer have been reported for de novo expression of MUC5AC (Buisine et al. 1996, 2001; Myerscough et al. 2001; Kocer et al. 2002; Warson et al. 2002) and MUC 20 overexpression (Xiao et al. 2013).