CD21

Expressed on B-cells and follicular dendritic cells. Co-receptor for Epstein Barr Virus (EBV) which explains why B-cells are typically the cells infected by EBV and not T-cells (T-cells lack CD21). Recall the CD_Mnemonic, "B" for "B-cells" & "Bigger" CDs (CD19, 20, 21, 22, 23, 24) which are typicaly expressed in "B-cells".

Note: Unfortunately the function and expression profile of CDs larger than CD24 need to be memorized.