Intermediate (GFP^lo) cells from neonates also produce greater levels of cytokine compared with intermediate (GFP^lo) cells from adults. (A) CD4⁺ LN cells from RAG2p-GFP^+/− neonates and adults were sorted into RTEs (GFP^hi), intermediate (GFP^lo), and resident (GFP⁻) populations. These purified neonatal (B) and adult (C) cells were then activated with PBαCD3 and αCD28 for 48 hours, and supernatants were harvested for cytokine-specific ELISA. (D) The data from panels B and C were regraphed to show a comparison of neonatal and adult RTEs and intermediate cells. Graphs represent pooled data from 4 or 5 independent experiments and are shown as the mean ± SEM; n = 35 to 60 neonates and 6 adults per experiment.