CD8A and breast cancer: Since the CD8/MUC1-MUCY co-immunoprecipitation experiments (Figure 3c) found MUC1-CD association in the absence of a CQC motif in the CD8/MUC1 partner, we sought to determine if CQC mediated dimerization was necessary for our observed constitutive MUC1 dimers in MUC1 full-length transfectants and breast cancer cell lines.