The protean output of Germany’s Isa Genzken gets its most extensive U.S. airing yet in this compelling retrospective of work made since the 1970s. Her biting sense of humor—one sculpture is titled Gay Babies—complements a thoroughgoing formal innovation. Any artist who can witness the 9/11 attacks, as Genzken did on one of her frequent visits to New York, and then make sculptures that crack jokes on the idea of a memorial, such as Osama Fashion Store (Ground Zero), 2008, deserves our attention.