Similarly, arterial stiffness as measured by PWV and AIx has been proven to be increased in SLE patients compared to controls [41,42,43] and this is related to both traditional risk factors—especially metabolic syndrome and age—and SLE-related risk factors, such as disease activity measured by SLEDAI, SLICC damage index, higher C3 levels, presence of ds-DNA antibodies, and glucocorticoid therapy [41,42,43,50,51,63,64] (Table 1). The gene discussed is C3; the disease is systemic lupus erythematosus.