pDCs that infiltrate breast cancers have been shown to be defective in producing IFN-α and to co-localize with T regulatory cells (T-reg, CD3+CD4+CD25+ FOXP3+) [158], suggesting that either T-reg cells may be inhibiting IFN-α production or that pDCs somehow support the proliferation of T-regs. Here, IFNA1 is linked to breast cancer.