The schematic indicates the trafficking patterns of several T cell populations. Naïve, and TCM cells recirculate through blood and SLOs, and enter LNs via HEVs. Some sub-populations of TEM recirculate from blood to nonlymphoid tissues, and pass through lymphatics and LNs on the way to rejoining the blood supply (recirc TEM, also referred to as TPM), while others are confined to recirculating in blood (bloodborne TEM). TRM do not recirculate, and are parked within nonlymphoid tissues, SLOs, and local vascular compartments.