LONDON, ENGLAND February, 2020: ‘XXI’, a landmark contemporary art exhibition, will launch at the new, state-of-the-art HOFA Gallery in London’s Mayfair on 20 February 2020.  It is set to be the world’s first ever asset-based tokenised contemporary art exhibition, using cutting-edge blockchain technology and cryptography to facilitate access to coveted blue-chip contemporary art. RETNA The highly anticipated highlights of…