Los Angeles, California - The official cause of death of Grey's Anatomy star Eric Dane has been revealed.

Last month, Dane tragically died of Amyotrophic lateral sclerosis, also known as ALS or Lou Gehrig's disease, at the age of 53.

According to People, the actor's official cause of death was respiratory failure.

Dane played Dr. Mark Sloan, nicknamed "McSteamy," on the hit show Grey's Anatomy.

Dane went public with his ALS diagnosis public in April 2025.

"I have been diagnosed with ALS. I am grateful to have my loving family by my side as we navigate this next chapter," he told People at the time.

ALS is a progressive degenerative disease impacting nerve cells in the brain and spinal cord, and the body gradually becomes paralyzed. There is currently no cure.

Recently, the actor was barely able to walk or speak.

The 53-year-old is mourned by his wife, Rebecca Gayheart, and their two daughters, Billie Beatrice (15) and Georgia Geraldine (13).