A sharp-eyed school nurse in New Jersey is credited with saving a young boy’s life after noticing the kindergartener had signs of leukemia.

Nathan Campbell started school last fall in Camden County at Zane North Elementary School.

His teacher took him to the nurse's office after the little boy said he didn't want to go outside and play, because his leg was hurting, according to CBS NY.

The nurse, Patti Butler, noticed something was wrong right away.

Butler said the problem was easy to spot.

"His skin was translucent, and that's when I said I've only seen someone look like this color once in 25 years. Prove me wrong," Butler told CBS.

But she wasn’t wrong. She suspected leukemia, and Nathan was soon diagnosed with the deadly cancer.

The boy’s mother, Nicole Defeo Campbell, credited the nurse with saving her son’s life.

“If she hadn’t called us, we would not be standing here talking about Nate today,” she said.

After treatment for leukemia, Nathan is now in remission, and his mother has nominated Butler for the America's Greatest School Nurse contest, But the nurse said she just wants the little boy to recover.