MUC5AC and colorectal mucinous adenocarcinoma: It is well known that the mucin protein family is highly expressed in mucinous colorectal adenocarcinoma,2 so the expression of secreted mucins (including MUC5AC, MUC5B, MUC6) and transmembrane mucins (including MUC1, MUC3A, MUC4, MUC12, MUC13, MUC15, MUC16, MUC17, MUC20) was detected in each cell cluster.