It was designed using the principle of entasis. The entasis, or curve, of its columns give a stronger visual presence. The feature was designed using the principle of entasis. The first known use of entasis was in the construction of Egyptian pyramids. It is being developed by Entasis Therapeutics and is currently in Phase II clinical trials. Except for those in the facade, the columns lack entasis. "Entasis" refers to the subtle diminution in diameter of the columns as they rise.