VSMCs which undergo phenotypic modulation may genetically shift their expression to fibroblast-like cells under the positive-regulation of Tcf21. Genome-wide association studies (GWAS) demonstrated that genetic variants of Tcf21 is causally associated with coronary artery disease, however, scRNA-seq may have elucidated a significant role for Tcf21 in phenotypic modulation (117, 127). This evidence concerns the gene TCF21 and coronary artery disorder.