MUC1 and neoplasm: MUC1-deficient PDAC exhibits significant different immune reaction compared to wildtype PDAC in mouse models [27], and MUC1 absence results in the proliferation and activation of myeloid-derived suppressor cells (MDSC) and regulatory T cells (Treg), which correspond to the immunosuppressive tumour microenvironment and are responsible for tumour immune evasion [28].