New York Rep. Lee Zeldin (R) on Saturday announced that he was diagnosed with leukemia last year and that it is in remission following treatment.

Zeldin's diagnosis had not been disclosed before this weekend, even as he announced his intentions to run for New York governor.

“Through early detection, last November, I was diagnosed with early stage chronic myeloid leukemia (CML). I then began treatment with an immediately positive response and no side effects. Over the last 9 months, I have achieved complete remission, am expected to live a normal life, and my doctor says I currently have no evidence of this disease in my system. My health is phenomenal and I continue to operate at 110%," Zeldin said in a statement shared on his campaign website.

According to the American Cancer Society, CML is a type of cancer that forms in certain blood-forming cells of the bone marrow and affects red blood cells, platelets and white blood cells. The cancer is regarded as being relatively slow-growing, but can advance into a fast-growing leukemia.

One large study found that around 90 percent of CML patients were still alive five years after starting treatment and were found to have normal white blood cells.

Zeldin's physician, Dr. Jeffrey Vacirca, said the congressman is "incredibly healthy" and now has a normal life expectancy.

The New York congressman announced his bid for governor in April in an effort to oust then-Gov. Andrew Cuomo (D-N.Y.). Cuomo resigned in August, resulting in then-Lt. Gov Kathy Hochul (D) becoming the first female governor of New York.

In June, New York Republican officials voted to name Zeldin as the GOP's presumptive gubernatorial nominee, ahead of the party's primary election.

Zeldin faces an uphill battle in New York, where a Republican governor has not been elected in nearly two decades. However, the recent resignation of Cuomo has given the GOP hope that Republicans have a stronger chance in this election.