ISG15 and breast cancer: Using CD45-/CD31+ TECs from E0771 mammary tumors, we could also identify a mitotic cluster, marked by Top2a, that was enriched in Dnmt1 relative to the other clusters; notably, this cluster was distinct from a second cluster that resembles a recently described IFN response EC cluster represented by genes such as Irf8, Ifit2, Isg15, and Cxcl10 (Supplementary Fig. 17a–d)41.