The blood vessel network transfers gas and nutrients throughout the body. In addition, vascular cells contribute to essential functions such as coagulation, immune regulation, angiogenesis and tissue repair, and regulate vascular contractility and blood flow. However, the characteristics of the different vascular cell populations are largely unknown. In a recent study in Nature Medicine, Barnett et al. integrated single-cell transcriptomics data from 19 human organs and tissues and define 42 vascular cell states, including their genetic signature and regulatory networks. In addition, they predicted druggable cell targets and intercellular signaling that drives the endothelial–mural cell crosstalk.