CD4 and breast carcinoma: Likewise, recombinant MUC1 mucins glycosylated in a manner equivalent to those expressed on breast carcinoma cells and natural MUC1 mucins in supernatants of human pancreatic carcinoma cell lines both suppress IL-12 production and promote IL-10 production by monocyte-derived DC, and these regulatory DC are poor stimulators of T cell proliferation and CTL activity but potent inducers of T cell anergy and CD4+ Tregs (121, 122).