Expression of FcRL6 on PBMCs. (A) FcRL6 is expressed on CD56^dim NK cells, a subset of CD56⁺ CD3⁺ NKT cells, and a subset of CD8⁺ T cells. In healthy individuals, FcRL6 is typically not expressed by CD4⁺ T cells, B cells, or monocytes. The lack of FcRL6 staining on CD14⁺ monocytes is indicated on the histogram (black line) overlaying the isotype control (gray line). (B) CD8⁺ T cells, purified by immunomagnetic isolation, were examined by 4-color flow cytometry to determine FcRL6 expression among CD8⁺ T-cell subsets. Expression of FcRL6 is found among CD28⁺ CD45RA⁻ 2B4⁺ effector-memory cells and CD28⁻ CD45RA⁺ 2B4⁺ effector cells. FcRL6 is not expressed by CD28⁺ CD45RA⁺ 2B4⁻ naive cells, or by CD28⁺ CD45RA⁻ 2B4⁻ central memory cells.