AbbVie CEO Richard Gonzalez, who grew the company into a pharmaceutical juggernaut, is preparing to retire. Crain's health care reporter Katherine Davis talks with host Amy Guth about the leadership change and the drugmaker's M&A plans.Plus: Allstate looks to unload Wacker Drive office building, Northwestern grad students reach first tentative union contract deal, Mag Mile retail space sold to firms known for amassing distressed malls and Duckworth moves to protect in vitro fertilization after Alabama ruling.Crain's Daily Gist listeners can get 20% off a one-year Crain’s Chicago Business digital subscription by visiting chicagobusiness.com/gist and using code “GIST” at checkout.