Singer, lupus advocate, and most-followed person ever on Instagram shared the news with fans and the public.

Actress and singer Selena Gomez revealed in an Instagram post that she had received a kidney transplant for her lupus in June.

In the post, she revealed that the kidney was donated by her good friend, actress Francia Raisa, writing:

“She gave me the ultimate gift and sacrifice by donating her kidney to me. I am incredibly blessed. I love you so much sis.”

Previously, in August 2016, Gomez had canceled the remaining dates of her tour when complications from her lupus caused her additional anxiety and depression. “It was what I needed to do for my overall health,” she wrote in the new post. “I honestly look forward to sharing with you, soon my journey through these past several months as I have always wanted to do with you.”

On Twitter, friends and fans alike are cheering Gomez for being open about her condition. Many consider lupus to be an “invisible illness” due to its often hidden symptoms and how difficult it can be to diagnose.

Gomez is one of many celebrities who’ve come out in recent years as living with invisible illnesses, including fellow singers and lupus survivors Toni Braxton and Kelle Bryan. And just days prior to Gomez’s transplant announcement, Lady Gaga made waves when she announced on Twitter that she’s living with fibromyalgia, another invisible illness.

Lupus is an autoimmune disease that causes inflammation. It’s a difficult condition for doctors to diagnose and has a variety of symptoms which affect people with different levels of severity. There are several types of lupus, including systemic lupus erythematosus (SLE), the most common type.

SLE can cause the immune system to target the kidneys, particularly the parts which filter your blood and waste products.

Lupus nephritis usually starts during the first five years of living with lupus. It’s one of the most serious complications of the disease. When your kidneys are affected, it can also cause other pains. These are the symptoms Selena Gomez likely experienced during her journey with lupus:

Lupus nephritis has no cure. Treatment involves managing the condition to prevent irreversible kidney damage. If there’s extensive damage, the person will require dialysis or a kidney transplant. About 10,000 to 15,000 Americans receive a transplant each year.

In her post, Gomez urged her followers to do their part to increase awareness about lupus and to visit and support the Lupus Research Alliance, adding: “Lupus continues to be very misunderstood but progress is being made.”