While initial studies focused on the role of GPR4 in supporting tumor angiogenesis [6], more recent data suggest a broader role of the endothelium in sculpting the tumor microenvironment: Indeed, the blood vessel endothelium may allow lymphocyte extravasation, while endothelial cells act as immune modulators secreting lymphocyte‐attracting chemokines and inflammatory mediators [49]. The gene discussed is GPR4; the disease is neoplasm.