We began by comparing established transcriptomic profiles (Mackay et al., 2013) of antigen-specific CD69+CD103+CD8+ TRM cells isolated from the skin, lung, and small intestine after HSV-KOS, influenza virus (WSN.gB), or acute lymphocytic choriomeningitis virus (LCMV-Armstrong) infection, respectively, with their circulating effector memory T cell (TEM cell) and central memory T cell (TCM cell) counterparts. This evidence concerns the gene CD8A and infection.