Answer by taking a quote from the following article:

Dario Fo (Italian pronunciation: ['da:rjo 'fo]; 24 March 1926 - 13 October 2016) was an Italian actor-playwright, comedian, singer, theatre director, stage designer, songwriter, painter, political campaigner for the Italian left-wing and the recipient of the 1997 Nobel Prize in Literature. In his time he was "arguably the most widely performed contemporary playwright in world theatre". Much of his dramatic work depends on improvisation and comprises the recovery of "illegitimate" forms of theatre, such as those performed by giullari (medieval strolling players) and, more famously, the ancient Italian style of commedia dell'arte. His plays have been translated into 30 languages and performed across the world, including in Argentina, Chile, Iran, the Netherlands, Poland, Romania, South Africa, South Korea, Spain, Sri Lanka Sweden, the UK and Yugoslavia.

An eldest child, Fo was born at Sangiano, in Lombardy's Province of Varese, near the eastern shore of Lago Maggiore. His younger brother Fulvio would become a theatre administrator, their younger sister Bianca Fo Garambois, a writer. Their mother, Pina Rota Fo, from a peasant background, wrote a book of reminiscences of the area between the wars, Il paese delle rane (Land of Frogs, 1978). Their father, Felice, was a station master for the Italian state railway, and the family frequently moved along the Swiss border when Felice was transferred to new postings. Felice, a socialist, was also an actor, appearing for an amateur theatre company in works by Ibsen among others. Fo learned storytelling from his maternal grandfather and Lombard fishers and glassblowers. Among the places in which Fo lived during his early years was Porto Valtravaglia, a glassblowing colony in which, it has been claimed, resided the highest percentage of insane people in Italy. In 1942, Fo moved to Milan to study at the Academy Brera Academy. However, the Second World War intervened. Fo joined the fascist army of Mussolini's Repubblica Sociale Italiana. Years later, Fo did not deny this affiliation but supported this moot thesis: he did it to avoid arousing suspicion, because his family was active in the anti-fascist Resistance and Fo helped his father to smuggle refugees and Allied soldiers to Switzerland by disguising them as Lombard peasants. His father is also thought to have helped smuggle Jewish scientists to the safety of Switzerland. As the end of the war approached, Fo joined an anti-aircraft division of the navy, anticipating an immediate discharge due to a shortage of munitions. He was mistaken and was instead dispatched to a camp in Monza at which Benito Mussolini himself arrived. Fo soon deserted with the aid of false documents and wandered for a while before joining a parachute squadron. He then deserted this as well, prompting a further unsuccessful search for the Resistance movement during which he slept rough in the countryside. After the war Fo returned to the Brera Academy, also taking up architectural studies at the Politecnico di Milano. He started a thesis on Roman architecture, but becoming disillusioned by the cheap impersonal work expected of architects after the war, he left his studies before his final examinations. He had a nervous breakdown; a doctor told him to spend time doing that which brought him joy. He began to paint and became involved in the piccoli teatri (small theatres) movement, in which he began to present improvised monologues. He considered his artistic influences to include Beolco, Brecht, Chekhov, De Filippo, Gramsci, Mayakovsky, Moliere, Shaw and Strehler.

Did Dario Fo have any other family besides his parents?
younger brother Fulvio