To gain insight into whether tumor cells themselves are the primary source of Ereg and Areg, we used magnetic cell sorting to isolate IGFIR+ tumor and non-epithelial lineage cells (IGFIR-/CD31+/CD45+/Tert119+/BP1+) containing mixed stromal cell populations (hematopoietic, endothelial, fibroblast) followed by qPCR (S2 Fig). The gene discussed is PECAM1; the disease is neoplasm.