Circulating levels of C3 complement were significantly elevated (p < 0.001) in subjects with a genetic diagnosis of FH and subclinical coronary atherosclerosis, when compared to the plasma levels of C3 in young healthy subjects at low atherosclerotic risk (subjects without CV risk factors and age between 18 and 35 years) (Figure 1A). Here, C3 is linked to coronary atherosclerosis.