Madonna's older brother Anthrony Ciccone died Friday at 66.
He'd been suffering from alcoholism and had been experiencing homelessness, according to the BBC.
The pop icon took to Instagram to pay tribute to her brother on Monday.
In an Instagram story, she posted a photo fo the two of them with their other siblings. "Thank you for blowing my mind as a young girl," Madonna wrote. "You planted many important seeds."
She added that Ciccone introduced her to Charlie Parker, Miles Davis, Buddhism, Taoism, Charles Bukowski, Richard Brautigan, and Jack Kerouac.
The pop star's brother-in-law, singer-songwriter Joe Henry, announced the news on Instagram on Saturday. Henry is married to Madonna's sister, Melanie Ciccone.
“My brother-in-law, Anthony Gerard Ciccone, exited this earthly plane last evening," Henry wrote. "I’ve known him since I was 15, in the spring of our lives in Michigan so many years now gone. As brother Dave Henry (who took this photograph) notes here, Anthony was a complex character; and god knows: we tangled in moments, as true brothers can. But I loved him, and understood him better than I was sometimes willing to let on.
"But trouble fades; and family remains— with hands reached across the table. Farewell, then, brother Anthony. I want to think the god your blessed mother (and mine) believed in has her there, waiting to receive you. At least for today, no one shall dissuade me from this vision.”
He also shared an older photo of Anthony with the post.
A cause of death hasn't been reported.
A source told People magazine, “They were all there for him and despite being estranged, Madonna supported him in every way she could when he was willing to take the support. Family members including Madonna visited him while in his rehab facility as he declined these past few months.”