On Thursday, Taylor Swift shared some very sad news on her Tumblr: Her mother, Andrea, has been diagnosed with cancer.

The news was followed by an outpouring of condolences, love and support from fans. #PrayForMamaSwift — a hashtag started by Shawn Mendes, the opener on her upcoming tour — was trending on Twitter all day.

Among those praying for Swift is Lady Gaga, who tweeted her support for the country-turned-pop star.

Aside from sharing the cancer diagnosis, Swift said she’d “like to keep the details of her condition and treatment plans private.” The 1989 singer urged her fans to get their parents screened, pointing out that it’s easier to beat cancer if you catch it early.