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

Most recently, Pope Leo XIV was diagnosed with lung cancer after undergoing surgery to remove the lower lobe of his right lung.

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

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 Francis appointed him to one of the Vatican's most influential positions.

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.

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.

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.

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.

His first encyclical, a letter written by the Pope for guidance, addressed AI.

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.

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.

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