Figure 1. Pre-RTEs consist of SP4 thymocytes in adult mice but a mixture of SP3 and SP4 thymocytes in neonatal and young mice.

A. FITC intrathymic injection of C57BL/6 mice were used to analyze the phenotype of RTEs (FITC⁺ cells) at 2, 4, and 6 weeks of age. B. RAG2p-GFP mice were also used to study RTEs (GFP^hi cells). The numbers in the plot represent the mean and standard deviation of the ratios of Qa2⁺CD69^- cells in FITC⁺ or GFP^hi CD4⁺CD8^- T cells in the lymph nodes (LN) and spleen. Three to five mice were analyzed.