Importantly, results from a study on a 4T1 murine breast cancer model showed that CD20+ B-cell depletion by anti-CD20 mAb infusion provoked preferential enrichment with CD20LowCD137Low regulatory B-cells leading to tumor progression and metastasis, thus demonstrating the essential role of B-cells in disease control [100]. This evidence concerns the gene MS4A1 and neoplasm.