ATLANTA — Former Atlanta Hawks player Jason Collins has announced he is battling an aggressive form of brain cancer.

The 47-year-old says he is receiving treatment for stage-4 glioblastoma. Collins shared that he first began experiencing symptoms in August, when he noticed problems with his short-term memory.

Collins made history as the first openly gay player in NBA history. During his 13-year professional career, he played for six teams, including the Atlanta Hawks.

Collins says he is vowing to fight the disease as he undergoes treatment.