(TIML NEWS) Here’s why Selena Gomez has been laying low lately. The “Good For You” singer revealed on Thursday she received a kidney transplant recently to help with her Lupus disease. The donor, you might ask? Her longtime sister-friend, actress Francia Raisa.

“I’m very aware some of my fans had noticed I was laying low for part of the summer and questioning why I wasn’t promoting my new music, which I was extremely proud of. So I found out I needed to get a kidney transplant due to my Lupus and was recovering. It was what I needed to do for my overall health. 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,” she stated via Instagram.

She went on to thank all parties involved, from her family to her caregivers, especially Raisa: “Until then I want to publicly thank my family and incredible team of doctors for everything they have done for me prior to and post-surgery. And finally, there aren’t words to describe how I can possibly thank my beautiful friend Francia Raisa. She gave me the ultimate gift and sacrifice by donating her kidney to me. I am incredibly blessed. I love you so much sis.”

Gomez first revealed she suffered from Lupus in a 2015 issue of Billboard. She even shared that she had to undergo chemotherapy to deal with her condition.

“Lupus continues to be very misunderstood but progress is being made,” Gomez reiterated in the same IG message. “For more information regarding Lupus please go to the Lupus Research Alliance website: http://www.lupusresearch.org/ -by grace through faith”

Raisa, 29, starred on The Secret Life of the American Teenager and will reportedly star in the Black-ish spin-off, Grown-ish. She and Gomez have been friends since 2008.