Breast and pancreatic cancer patients may spontaneously develop a specific, MHC-independent cytotoxic T-cell response against epitopes in the protein core of tumour-associated MUC1 (Jerome et al, 1991); however, MHC class I and class II restricted cellular immune reactions against MUC1 protein were observed as well (Apostolopoulos et al, 1997; Hiltbold et al, 1998; Reddish et al, 1998; Brossart et al, 1999; Pietersz et al, 2000; Heukamp et al, 2001). Here, HLA-C is linked to neoplasm.