CD4 and viral infectious disease: The observation that expanded clones of latent cells are frequently found in the CD4+ TEM compartment is consistent with the finding that clones of latent cells and TEM cells develop in response to chronic viral infection (Farber et al., 2014; Harari et al., 2004, 2005; Mendoza et al., 2020; Simonetti et al., 2021; Stubbe et al., 2006; Weng et al., 2012).