Related Co., Oxford Property Group and Mitsui Fudosan have signed leases with tenants for the top and bottom of 55 Hudson Yards.

Third Point, an $18B hedge fund run by Dan Loeb, signed a 10-year lease to occupy 75K SF, comprising the 50th and 51st floors of the building, as well as half of the 49th. Mount Sinai Medical Center has also agreed to operate a concierge medical facility on the second floor, the New York Post reports.

The medical center will reportedly be for exclusive use by residents and employees at Hudson Yards. Related CEO Jeff Blau is a board member at Mount Sinai and arranged the deal himself, Lois Weiss reported for the Post.

55 Hudson Yards is scheduled to be complete in 2018. Mitsui Fudosan purchased a 92% stake in the building for $236M in 2015, which it followed up with a purchase of 90% of 50 Hudson Yards as part of a $3.6B financing package.

Third Point will be moving to the 1.3M SF building when its lease at 390 Park Ave., also known as Lever House, expires. The 1950s-era building was one of the first to have glass curtain walls, a now-ubiquitous style that Hudson Yards employs, but it is currently locked in a foreclosure battle.

RFR owns the building on a 99-year ground lease, one in which the rent is set to spike dramatically just as a number of its tenant leases, including Third Point's, expire. Such a confluence of circumstances has made lenders unwilling to refinance RFR's loans.

Third Point joins an investment-heavy tenant list at 55 Hudson Yards, sitting atop Silver Lake and Point72 Asset Management, among others.