FCER2 and neoplasm: Previous studies have shown that B cells play an important role in tumour progression; for example, compared with that in peripheral blood, the number of memory B cells and antibody-secreting B cells in the tumour microenvironment (TME) is increased, and the expression of B-cell surface markers is also different, e.g., CD23 is downregulate and CD86 is upregulated in breast cancer [17].