We downloaded publicly available microarray gene expression data on 292 immune cell types from the ImmGen Consortium (see URLs). We used both Phase 1 (GSE15907) and Phase 2 (GSE37448) data. The data on GEO were on an exponential scale, so we log transformed the data and mapped to human genes using ENSEMBL orthologs. We defined tissue categories for t-statistic computation using the classification on the main page of immgen.org of cell types into categories: B cells, gamma delta T cells, alpha beta T cells, innate lymphocytes, myeloid cells, stromal cells, and stem cells (Table S10). The classification at immgen.org also has a “T cell activation” category that we collapsed into the alpha beta T cell category because it had data on alpha beta T cells at different stages of activation. We did not include any covariates.
