The president of the National Association of Realtors abruptly resigned after a blackmail threat. Crain’s residential real estate reporter Dennis Rodkin talks with host Amy Guth about that and other local housing news, including a condo that rents for $30,000 a month filled with music and pop culture memorabilia.Plus: Boeing CEO fights back tears and admits 'our mistake' in 737 address, trio of companies set to leave troubled Wacker Drive office tower, new device at UChicago can smash liver tumors with bubbles caused by sonic pulses and Rush plans new $27 million medical office in Lakeview.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.