IL10 and neoplasm: More abnormally, using an enzyme-linked immunospot (ELISpot) detection system, we observed that the FcγRIIlow/− B cells, but not the FcγRIIhigh B cells, without additional stimulation, were the major source of IL-10 production in tumour B cells (Fig. 1f), which is in contrast to observations in mouse model that the FcγRIIhigh B cells were the major source of IL-10 production16.