More than 500 people turned out in Selden Sunday to see if they were a match to donate bone marrow to a boy not fully responding to chemotherapy.

As News 12 reported, three-year-old Nicky Mauceri was diagnosed with Acute Lymphoblastic Leukemia in January.

DKMS, an organization that combats blood cancer, administered the donor tests Sunday.

Nicky's mother, Denise, says he hasn't fully responded to chemotherapy, and doctors now consider him to be high risk.

The event had such a great turnout that DKMS actually ran out of testing kits. But, DKMS Donor Recruitment Coordinator Jordan Segal says finding a match isn't easy.

"Essentially you are looking for your genetic twin," he says. "Less than one percent of people who register are actually found to be a match."