Table 1. . Memory immune cell subsets.

Subset name	Location	Blood trafficking	Lymph node trafficking	Function
Tcm	Lymphoid organs	Yes	Yes	Enhance likelihood of specific T cell–APC encounters and magnitude of the secondary immune response
Tem	Nonlymphoid organs	Yes	No	Effector function in chronic and secondary reinfection
Trm	Nonlymphoid organs	No	No	Direct tissue immune response and immune surveillance
Bm	Germinal center lymphoid organs	Yes	Yes	Secondary humoral immune response

This table summarizes the main subsets of immune memory cells with their localization and functions.

APC: Antigen-presenting cell; Bm: Memory B lymphocyte; Tcm: Central memory T cell; Tem: Effector memory T cell; Trm: Tissue-resident memory T cell.