Which structure is indicated by the arrow on this image of a normal valve?

The arrow points to the left coronary cusp of the aortic valve, identifiable in the short axis view as one of the three cusps. The left coronary cusp is adjacent to the left coronary artery origin and lies anteriorly.

The posterior leaflet is part of the mitral valve, septal leaflet refers to the tricuspid valve, and non-coronary cusp is another aortic cusp located posteriorly.

This identification is found in the "Textbook of Clinical Echocardiography, 6e", Chapter on Aortic Valve Anatomy【20:50-55†Textbook of Clinical Echocardiography】.