Hebbel RP, Wei P, Milbauer L, et al. - This study is done to test whether a unique approach to acquire a better understanding of heritable risk for early atherosclerosis—surveying gene expression by endothelial cells from living people—is feasible. Coronary reactivity testing was done in people aged < 50 years without obstructive coronary artery disease in order to recognize them as having normal or abnormal coronary endothelial function. For microarray evaluation of gene expression, cultures of Blood Outgrowth Endothelial Cells from 6 normal and 13 abnormal people were used. It is predicted by the known pathogenic impacts of high‐HMGB1 (high mobility group box 1) and low‐LAMC1 (laminin gamma 1) that the combination would biologically converge upon the focal adhesion complex, ultimately resulting in impairment of endothelial shear responsiveness. A heritable risk state encouraging early coronary atherosclerosis may be comprised in this gene expression pattern. If so, the use of the testing could be possible even in childhood, allowing early intervention. This approach affords a means to bridge the information gap between genetics and clinical phenotype.