CD8A and acute lymphoblastic leukemia: To test the possibility that our findings from the comparison between T-ALL cells and healthy CD8+ T cells in the spleen (Fig. 1c, d and Supplementary Fig. 2e–h) could reflect developmental differences between immature thymocytes, from which T-ALL arises, and splenic T cells, we compared the transcriptomes of healthy thymocytes to healthy splenic CD8+ T cells, and found that integrin-associated pathways were not enriched in thymocytes (Supplementary Fig. 3a).