CEACAM5 and neoplasm: Collectively, we show that in our system IL-12 and IL-27 have non redundant roles in modulating the polarization of established CEA-specific Th2 CD4+ T cells and that modulation of the functional and phenotypic Th2 polarization of anti-tumor CD4+ effectors into a Th0 type was obtained only in the presence of the combined synergistic treatment with the two cytokines.