Composite candidate genes and siRNA-based screen of VWF supernatant and lysate levels after target gene knockdown. (A) Circos plot demonstrating overlap of candidate genes from the most highly differentially expressed genes for 3 independent differential expression analyses: (1) control EC vs low VWF ECFCs (subject level-expression analysis), (2) all cell-expression analysis, and (3) control EC-expression analysis. Genes are visually shown as composing the shaded outer circle (green, differentially expressed genes in subject level-expression analysis; red, differentially expressed genes in the All cells-expression analysis; blue, differentially expressed genes in the Control EC-expression analysis). The dark orange shading on the inner circle represents genes that are represented in more than 1 analyses and are connected to overlapping genes in another analysis via purple lines. Light orange shading represents genes that are unique to only that differential expression analysis. (B) Candidate genes were assessed to determine effects on VWF protein levels in HUVECs via an siRNA-knockdown assay. After transfection with 1 nM candidate siRNAs (2-4 siRNAs per gene), VWF protein levels were assessed in the cellular lysates and cellular supernatants via a VWF enzyme-linked immunosorbent assay. Values are reported as percentage expression of control scrambled siRNA. For all experiments, N > 3, and P values of significant relationships are shown as analyzed by a 1-way analysis of variance with Holm-Sidak’s multiple comparison test. Error bars represent means ± standard error of the mean. Statistical significance is shown with asterisks compared with control siRNA (*P < .05, **P < .01, ***P < .001, ****P < .0001).