B cells, B-cell, B-cell populations, Breg, Breg cells, Breg-, Breg-cell, Breg-cell surface proteins, CD19, CD19+CD39IL10+ B-cell population, CD24, CD24hiCD38hi, CD38, CD39, CD39IL10, CD4, CD4+FOXP3+ regulatory T-cell, FOXP3, H-chain, IL10, IL10-producing B regulatory (Breg)-cell subset, IL21, IgG, T effector, T follicular helper, T follicular helper-cell, Tumor-Associated CD19+CD39- B Regulatory Cells, breast cancer, cancer, class, class-switched memory B cells, cytidine, cytidine deaminase, germinal, high, high-affinity antibody-producing plasma B cells, patients, serum-IgG, tumor, tumor-associated Breg cells, tumor-specific CD19+CD24hiCD38hi