The importance of long-lived IgE plasma cells for protracted allergies.

IgE contributes to allergy, but its cellular sources are rare and hard to identify. Genetic fate mapping and single-cell sequencing approaches have now revealed that two cell populations maintain IgE: long-lived IgE plasma cells (PCs) and 'type 2' memory B cells. This forum piece discusses recent discoveries on long-lived IgE PCs.