MUC5B and carcinoma: Therefore, we hypothesize that the absence of increased immune infiltration observed in LS-174T MUC2 K.O. is due to the presence of those other mucin proteins in the ECM, in line with the presence of MUC5B and MUC6 being significantly over-expressed (with lower fold change and p-value than MUC2) genes in mucinous adenocarcinoma compared to other carcinomas.