Total RNA was extracted from frozen tissues of 5 Eμ-myc lymphomas per TRAIL-R genotype (i.e., WT, TRAIL-R^+/–, and TRAIL-R^–/–) using the RNeasy mini kit (Qiagen). Complementary DNA was synthesized from total RNA using a dT primer tagged with a T7 promoter. Complementary RNA was synthesized by transcription in vitro and labeled with biotinylated nucleotides (Enzo Biochem). All hybridizations were performed using the MOE430A 2.0 GeneChip (Affymetrix). Gene lists, filtered by a minimum of 2-fold change (1-way ANOVA, P < 0.05), were generated with the GeneSpring GX 7.3.1 software (Agilent), which resulted in the creation of gene structures specific to WT and TRAIL-R–deficient mice (total of 59 genes, 17 upregulated and 42 downregulated). Also, more stringent exclusion criteria were applied by the use of significance analysis of microarrays (SAM) software version 2.0 (with an approximate 26.7% false discovery rate) and filtering against gene lists for signal transduction pathways, apoptosis-related genes, and oncogenes obtained from the Gene Ontology Consortium in order to detect 6 differentially expressed genes.