SRX1435183 GSM1942801 SRP066315 SRS1166369 GSM1942801 RNA-Seq TRANSCRIPTOMIC cDNA Cells were washed, stained and sorted for CD3 (Biolegend), CD4 (Biolegend), 7AAD and IL-17A-GFP+. population controls were generated by extracting total RNA using a RNeasy plus Micro RNA kit (Qiagen) according to manufacturer’s recommendations. Subsequently, 1 μL of RNA in water was added to 2 μL of lysis reaction mix, thermocycled using cycling conditions I described in Supplementary Experimental Procedures in corresponding publication. Next, 4 μL of the RT Reaction Mix were added, and the mixture was thermocycled using cycling conditions II. Finally, 1 μL of the total RT reaction was added to 9 μL of PCR mix, and that mixture was thermocycled using cycling conditions III. Products were quantified, diluted to 0.125 ng/ μL, and libraries were prepared, cleaned, and tested as described in Supplementary Experimental Procedures in corresponding publication. Illumina Genome Analyzer II gds 301942801 GEO Accession GSM1942801 SRX1435184 GSM1942802 SRP066315 SRS1166368 GSM1942802 RNA-Seq TRANSCRIPTOMIC cDNA Cells were washed, stained and sorted for CD3 (Biolegend), CD4 (Biolegend), 7AAD and IL-17A-GFP+. population controls were generated by extracting total RNA using a RNeasy plus Micro RNA kit (Qiagen) according to manufacturer’s recommendations. Subsequently, 1 μL of RNA in water was added to 2 μL of lysis reaction mix, thermocycled using cycling conditions I described in Supplementary Experimental Procedures in corresponding publication. Next, 4 μL of the RT Reaction Mix were added, and the mixture was thermocycled using cycling conditions II. Finally, 1 μL of the total RT reaction was added to 9 μL of PCR mix, and that mixture was thermocycled using cycling conditions III. Products were quantified, diluted to 0.125 ng/ μL, and libraries were prepared, cleaned, and tested as described in Supplementary Experimental Procedures in corresponding publication. Illumina Genome Analyzer II gds 301942802 GEO Accession GSM1942802