Runners looking to test their vertical limits can set their sights on 4 World Trade Center.

The Damon Runyon Cancer Research Foundation began enrollment Tuesday for a charity stair race up the 72-story skyscraper on April 3.

Interested applicants can chose to run to the 72nd or 54th Floor or opt for the virtual climb and take the elevator to the top of the building that opened in November.

Runners must pay a $40 entry fee and reach a $72 fundraising minimum to qualify.

Proceeds from the race will to go to the charity, which conducts cancer research. You can visit www.damonrunyon.org for details.