Flow cytometrically purified T cell precursors of C57BL/6 mice. RNA was labeled by double round in vitro transcription-based RNA amplification. Images were analyzed with Affymetrix MAS 4.0. Files contain unnormalized AvgDiff values. Surface marker phenotype: CD44-CD25-CD4+CD8+large Replicate number: 3 (Note: all samples with identical replicate numbers are derived from the same vial of cells).