How did Queen Isabella son John die?

Queen Isabella of Castile's son, John, Prince of Asturias, died in 1497 under mysterious circumstances at the age of 19. He had been married to Margaret of Austria just months before his death. The exact cause of his death is uncertain, with suggestions ranging from illness to potential poisoning, but no definitive conclusion was reached. His untimely death was a significant blow to Isabella and her husband, King Ferdinand, as he was their only surviving male heir at the time.