Jane Fonda announced Friday that she has been diagnosed with cancer.

"So, my dear friends, I have something personal I want to share. I've been diagnosed with non-Hodgkin's Lymphoma and have started chemo treatments," the "Grace and Frankie" star, 84, wrote in an Instagram post.

"This is a very treatable cancer," she continued. "80% of people survive, so I feel very lucky."

Fonda said her chemotherapy will last six months and she is handling it "quite well" thus far, adding, "... Believe me, I will not let any of this interfere with my climate activism."

"Cancer is a teacher and I'm paying attention to the lessons it holds for me," the actress wrote. "One thing it's shown me already is the importance of community. Of growing and deepening one's community so that we are not alone. And the cancer, along with my age -- almost 85 -- definitely teaches the importance of adapting to new realities."

Fonda called herself "lucky" for having health insurance and access to the top doctors and treatments, two things she said "far too many people" don't have.

"I realize, and it's painful, that I am privileged in this," she wrote.

According to the National Cancer Institute, non-Hodgkin lymphoma begins in the cells of the lymph system, which is part of the immune system and helps the body fight infection and disease. It can occur almost anywhere as lymph tissue is found all throughout the body.

Fonda previously underwent a lumpectomy after being diagnosed with breast cancer in 2010. In 2018, she revealed she had a cancerous growth removed from her lip.