Drug-target MR supported strong protective associations for genetically proxied inhibition of TRL-pathway targets, particularly <i>APOC3</i> and <i>LPL</i>, with AAA risk.<h4>Conclusions</h4>TRLs are at least threefold more aneurysmogenic than LDLs on a per-particle basis. The gene discussed is APOC3; the disease is triple-A syndrome.