Passage: In December 1976, Eden felt well enough to travel with his wife to the United States to spend Christmas and New Year with Averell and Pamela Harriman, but after reaching the States his health rapidly deteriorated. Prime Minister James Callaghan arranged for an RAF plane that was already in America to divert to Miami, to fly Eden home.Eden died from liver cancer in Salisbury on 14 January 1977, aged 79. He was survived by Clarissa.He was buried in St Mary's churchyard at Alvediston, just three miles upstream from 'Rose Bower', at the source of the River Ebble. Eden's papers are housed at the University of Birmingham Special Collections.At his death, Eden was the last surviving member of Churchill's War Cabinet. Eden's surviving son, Nicholas Eden, 2nd Earl of Avon (1930–1985), known as Viscount Eden from 1961 to 1977, was also a politician and a minister in the Thatcher government until his premature death from AIDS at the age of 54.

Question: What did her son die of?
AIDS