CD22 and neoplasm: Lastly, expression of CD22, which functions as an inhibitory receptor for B-cell receptor signaling[23] was low on ~98% of BCWM.1 tumor cells (MESF 15,665.8), lesser so on 63% of MWCL-1 cells (MESF 2,819.4) and scarcely present on 20% of RPCI-WM1 cells (MESF 958.8).