Differential expression of probe sets during deletional tolerance, immunity, and lymphopenia-induced proliferation. The Venn diagram depicts the differentially expressed probe sets detected on the array using the statistical analysis described in “Microarray data analysis” in “Methods.” The expression changes are split into probe sets up-regulated (+, left) and down-regulated (−, right) within each comparison. Tol.Naive represents probe sets differentially expressed within OT-I cells isolated from RIP-OVA^hi mice relative to the undivided cells recovered from unchallenged (naive) C57BL/6 mice. Imm.Naive and Rag.Naive show the same comparison for cells recovered from OCS/LPS and Rag^−/− mice, respectively.