A group of parents protested outside of NYU Winthrop Hospital Friday demanding the release of a 12-year-old Huntington boy.

Nicholas Gunderson was diagnosed with mixed phenotype acute leukemia, also known as MPAL, in July.

He is now at the center of a battle between Child Protective Services and his mother, Candace Gunderson.

Gunderson says CPS seized her son in September and is forcing him to undergo chemotherapy at Winthrop even though he is in remission.

"They don't want me to be able to exercise my freedoms to choose medical treatment for my child," says Gunderson.

Gunderson says doctors at Cohen Children's Medical Center misdiagnosed Nicholas' cancer, and gave him the wrong treatment. Gunderson says she told doctors she was taking her son to another facility for treatment.

"They proceeded to contact the police and CPS and explain that we were refusing all medical treatment for our child, which wasn't true," Gunderson says.

The mother says CPS took custody of Nicholas and he was transferred to Winthrop, where he received chemotherapy. Gunderson says on Oct. 8, doctors told her Nicholas' cancer was in remission.

"Which, at that time we decided, OK, he's in remission," she says. "We don't want him given any more chemotherapy for cancer when he doesn't have cancer in his body."

Gunderson says she took her son to Florida for holistic treatment, but when CPS found out, the agency took him back into custody on Oct. 30.

Nicholas is now back at Winthrop where Gunderson says he's receiving more chemo against her wishes.

CPS told News 12, "Child Protective Services is proceeding in accordance with the Suffolk County Family Court order and this matter will return to court on Wednesday.

A spokesperson for Northwell Health released a statement to News 12 saying: "Because of patient privacy, we can’t comment specifically on this case, other than to say that he was accurately diagnosed and provided appropriate treatment at Cohen Children’s Medical Center, and that we hope Nicholas receives the treatment he needs."