Kelley Mack, an actress best known for her work on the horror series “The Walking Dead,” has died at age 33. A representative for Mack confirmed her death to ABC News and said in a statement, “She will be so missed.”

Mack passed away in her hometown of Cincinnati, after suffering from a rare form of cancer that attacks your nervous system.

According to the New York Post, Mack was diagnosed in January with diffuse midline glioma, a rare, cancerous tumor. Mack documented her health journey on Caringbridge, which included having to relearn how to walk after losing the use of her right leg and most of her left.