TNF and neoplasm: (98) demonstrated that B-1 cells, when co-cultured with peritoneal macrophages, polarize them to a phenotype characterized by reduced expression of pro-inflammatory genes (such as Tnfa, Ccl3, and Il1b) in response to LPS stimulation, and an increase in the expression of the anti-inflammatory gene Il10. In the B16F10 melanoma tumor model, B-1 cells have been shown to polarize the macrophages present in tumors towards an alternatively activated pro-tumoral M2-like phenotype (98).