Especially relevant during the contraction phase of the immune response, a nomenclature has been proposed where CD127+/KLRG-1- cells are referred to as memory precursor effector cells (MPECs) and generally represent the cells with the greatest capacity to develop into central memory cells [30], whereas CD127-/KLRG-1+ cells are termed short lived effector cells (SLECs) and are associated with acute or ongoing infection. The gene discussed is IL7R; the disease is infection.