library_construction_protocol: 100,000 CD8 T cells were obtained from spleen/lymph nodes of mice and were activated with anti-CD3/anti-CD28 and treated as indicated. Total RNA was isolated from cells using the RNeasy Plus Micro Kit (Qiagen) following the manufacturer's protocol. Genomic DNA was removed using the gDNA Eliminator spin columns included in the kit. RNA concentration was measured using a NanoDrop spectrophotometer. Quality control and library preparation (poly(A) enrichment) were performed by the MSKCC Integrated Genomics Core.