We first isolated CX3CR1+ macrophages (CD45+CD14+CX3CR1+) and CX3CR1– macrophages (CD45+CD14+CX3CR1–) as controls from thoracic aneurysmal aortas of MFS patients (Supplemental Table 5) and directly measured the predicted ligands in the conditioned media of these patient-derived cells (Figure 3D). Here, PTPRC is linked to Marfan syndrome.