Pope Leo XIV has been diagnosed with lung cancer. Here's what to know about the first American pope.

He's 71 years old and was ordained to the priesthood in 1982. He has two brothers.

He's also a citizen of Peru, where he was first assigned in 1985, and later served as the Bishop of Chiclayo.

He studied at Villanova University and the Catholic Theological Union of Chicago. In 1984, he obtained his Canon Law licentiate, and in 1985, he defended his doctoral dissertation at the Pontifical University of Saint Thomas Aquinas.

Pope Leo XIV speaks English, Spanish, Portuguese, Italian, and French.

In 2023, the then-pope appointed then-Bishop Prevost as Prefect of the Dicastery for Bishops and president of the Pontifical Commission for Latin America, which plays a key role in bishop nominations.

In 2024, Pope Leo said in an interview with Vatican News that a "bishop is not supposed to be a little prince sitting in his kingdom, but rather called authentically to be humble, to be close to the people he serves, to walk with them and to suffer with them."

The process is known as the conclave. It took two days and four rounds of voting for the cardinals to agree on a new pope, per the AP.

Before the conclave, the National Catholic Reporter wrote that it was unlikely the US cardinal would become pope because of political implications. Yet Cardinal Prevost was considered a contender by others, especially as the week went on, ABC News reported.

Speaking from the balcony of St. Peter's Basilica, Pope Leo XIV said, "Peace be with all of you" in his first words in his new role. He spoke in Italian and then Spanish.

"My experience of Cardinal Prevost was that he's not a showboat," Father Mark R. Francis, who worked with Pope Leo in the past, told CBS News in 2025. "He's very calm, but extremely intelligent, and extremely compassionate."

He canonized Carlo Acutis and Pier Giorgio Frassati in September 2025, and made his first foreign trip to Turkey and Lebanon in November and December of that year.

Business Insider's Joshua Nelken-Zitser identified three main takeaways from the encyclical: the power of AI should not be monopolized by a small group; AI developers should ensure that what they are cultivating "is a genuine good"; and warnings that AI could lead to mass unemployment.

In addition to the encyclical, Pope Leo XIV has spoken about AI multiple times, including a recent address to artists and curators in which he said, "We urgently need to distinguish human art from what is produced by machines."

The pope underwent an operation to remove the lower lobe of his right lung, the Holy See press office said in October. It added that the surgery was successful with no complications.

The operation confirmed a previously suspected lung cancer diagnosis.

On Wednesday, the Holy See press office said the "night passed calmly" for the pope.