I had the happy experience recently of meeting a old friend named Helen. In her honor…
https://www.vaticannews.va/en/saints/08/18/st—helena–empress.html
Today’s saint is Helena, mother of Emperor Constantine …

Constantine the Great, Roman Emperor 307-337 [obverse]
Parisian 15th Century
National Gallery of Art, DC public domain
… and the rediscoverer of the True Cross around 327 A.D. Her pilgrimages to Jerusalem, where she demanded that Constantine build basilicas over the sites of Jesus’ crucifixion, burial and resurrection, also resulted in the eventual uncovering of the Cross upon which Jesus had died. A miraculous cure, pictured below, was the proof of the identity of the wood she had been shown.

Saint Helen Testing the True Cross. c. 1545. Tintoretto (Jacopo Robusti; Italian)
Art institute of Chicago — public domain
That’s all fascinating, but I did not realize that she is one of four special people honored in the four pilasters that support the dome of of the Basilica of Saint Peter and Saint Paul. Saint Longinus, Saint Veronica, and the Apostle Saint Andrew are the other three. Originally each person in the support had a special relic built in as part of the support. Saint Helena had a fragment of the true Cross, Saint Longinus had a fragment of the spear that pierced Jesus, Saint Veronica had her veil, and Saint Andrew’s skull was built into his support.
There’s a lot of food for thought and speculation here. Why Andrew? The general suggestion is that he was so honored because he was the first disciple, the one who ran to his brother, Peter, and told him he had to meet Jesus. Saint Andrew was martyred by being crucified on a specially shaped X-cross in Greece. In 1964, Saint Andrew’s skull was removed from Saint Peter’s and given back to the Greek Orthodox Church of Saint Andrew in Patras, Greece. It had been removed in the 1400’s when Greece was being invaded.
I can easily imagine that Saint Andrew was honored because an important relic needed a place to be housed. Even without his relic, itself, his story is important to remember. We should all be running around, telling people to come and meet Jesus.

The modern Church of Saint Andrew at Patras. https://www.romeartlover.it/Andrea.html
The header is from a church in Pennsylvania, honoring Saint Helena.