Manchester City’s fortunes changed dramatically with the takeover by Sheikh Mansour of Abu Dhabi. But after years of success, Europe’s governing body has banned the club from its most prestigious tournament, the Champions League. David Conn explains why. Plus: Alok Jha on the ethics of gene editing. Help support our independent journalism at <a href="https://www.theguardian.com/infocus">theguardian.com/infocus</a>