While several studies have provided evidence that differentiated effector Th1 and Tfh cells can give rise to long-lived memory cells, previous work further indicates that a memory precursor population develops among early responding CD4+ T cells and that this precursor population also significantly contributes to the establishment of durable and effective CD4+ T cell memory following resolution of the infection (Marshall et al., 2011; Pepper et al., 2011; Ciucci et al., 2019). The gene discussed is CD4; the disease is infection.