The Itineraries to the graves of the Roman martyrs (Giovanni Battista De Rossi, "Roma sotterranea", I, 180–1) also mention these two pieces of information.

[5] The Martyrologium Hieronymianum assigns him under the feast day of April 30, the date that appears in the catalogue of Roman martyrs of the 4th century.

A statue of Quirinus sits atop the church (which Jean-Baptiste Bernadotte attempted to plunder during the Napoleonic Wars[8]).

[2][3] His cult spread to Cologne, Alsace, Scandinavia, western Germany, the Netherlands, and Italy, where he became the patron saint of Correggio.

[3] Numerous wells and springs were dedicated to him, and he was invoked against the bubonic plague, smallpox, and gout; he was also considered a patron saint of animals.

[2][9][10] Portraits of Quirinus and of Valentine appear at the top of the recto of the Nuremberg Chronicles (Folio CXXII [Geneva]).