As shown in Figure 1B, this analysis showed significant variation between SLOs and GVHD target organs, and between target organs; for example, the cytotoxic genes Gzma and Gzmb were most highly expressed by gut TE, whereas a subset of proinflammatory cytokine genes (e.g., Tnf, Ifng, and Csf2) were mainly expressed by skin TE. This evidence concerns the gene CSF2 and graft versus host disease.