The Attiko Metro S.A., utilizing the "healing" properties of works of art, decorated the spaces where tens of thousands of people coexist daily, mostly strangers to each other, as they wait for the train that will serve them. It has integrated art into the everyday lives of citizens, adorning waiting areas with named works of art by great artists.

The friezes of the University Metro Station in Athens, Line 2, are adorned by the artistic intervention of "artist-philosopher" Giannis Moralis, which is permeated with the principles of a Hellenocentric modernism, a Doric simplicity of an archaic vocabulary, and a Byzantine austerity. It consists of a singular ancient Greek word, "ἅπαξ γεγραμμένη," found in the ancient Greek literature within the tragedy Heracles Mad by Euripides, which resounds loudly in the space of the Propylaea of the University of Athens: "hooded ones, throw off your masks." For the protection of his artwork alone, Giannis Moralis left it untitled.