In the present study, we evidenced elevated levels of circulating C3 in clinically asymptomatic patients with genetic diagnosis of FH and subclinical atherosclerosis (assessed by CTA) when compared with plasma levels in young healthy subjects, suggesting a maintained activation of the innate immune response in FH, although all patients were long-term treated with LLT as per the guidelines [27]. Here, C3 is linked to familial hyperaldosteronism.