- facilitating cells. Flow cytometric analysis of bone marrow FC stained with CD8α phycoerythrin, αβ-TCR fluorescein isothiocyanate, and γδ-TCR fluorescein isothiocyanate mAb. (A) FC comprised approximately 0.4% (range, 0.04% to 0.62%) of the total bone marrow and less than 1.6% of cells in the lymphoid gate. (B) The majority of cells in the FC are CD11c+/B220+/CD11b- p-preDC. FC: facilitating cells; p-preDC: plasmacytoid precursor dendritic cells; TCR: T cell receptor.