For nearly three decades, local developer John Rosenthal has been spinning one development dream after another for a gritty patch of urban real estate next door to Fenway Park.

In the fall of 1997, Rosenthal teamed up with Lansdowne Street club and entertainment mogul Patrick Lyons to propose a 14-story hotel and entertainment complex over the Turnpike, The Wall Street Journal reported at the time.

That plan went nowhere, and Rosenthal was soon back at it again, this time touting a new mega development involving the late Robert Redford and his now-defunct Sundance Cinemas chain.

And on and on it went over the years, with plans to build apartment towers over the Turnpike eventually giving way to proposals for a giant research complex.

About three years ago, Rosenthal became the junior/local partner to lab developer IQHQ, which proceeded to build out a $200 million deck over the turnpike for a pair of lab towers.

Now IQHQ has put on hold plans to build a $1 billion lab complex on the turnpike air-rights deck, per The Boston Globe which should know. After all, the paper happens to be owned by John Henry, whose holdings include neighboring Fenway Park and the Red Sox.

IQHQ is citing the collapse of the life sciences real estate market for its decision, with massive overbuilding of lab projects by developers having combined with a pullback by investors from biotech companies. But of course, per Rosenthal, there’s absolutely nothing to worry about. It will all get built in the end, though he can’t say when.

Someday, we guess. “Real estate is cyclical. I firmly believe that the towers will get built. They will house over 3,000 people every day. But I can’t say when,” Rosenthal told The Globe. “As soon as we have a significant tenant, we’ll build.”

Scott van Voorhis is a longtime Boston reporter specializing in real estate and is the publisher of Contrarian Boston.