Pumping blood with self-reliance and cooperation.

In this issue of JEM, Singhal et al. (https://doi.org/10.1084/jem.20180008) explore the cellular mechanisms involved in endothelial cell regeneration in the liver. Using a combination of myeloablative and nonmyeloablative approaches, the authors found that repair of the endothelium is mediated by endothelial cells themselves, but when injured, endothelial cells enlist myeloid counterparts that aid in vascular repair.