The different cell types of the lymphoid-myeloid lineage constitutively express various Fc receptors. The exception is the T-cell lineage where most subsets express Fc receptors only during a narrow window following cellular activation. M. Sandor and R.G. Lynch summarize information which identifies a multi-level relationship between Fc receptors and clonotypic T-cell receptors and conclude that this relationship might account for the restricted expression of Fc receptors on T cells.