They're back.

Girls Aloud has confirmed that they are planning to reunite for a charity event that is set to honour bandmate Sarah Harding. Cheryl, Nadine Coyle, Nicola Roberts and Kimberley Walsh are teaming up with Cancer Research UK to raise money for breast cancer research projects, especially the one Sarah wanted to help fund. Heading to her Instagram Story, Cheryl said that the group "desperately trying to find ways to help [Sarah]” when she was really sick, admitting “you feel so helpless in times like that.” “One of the only things [Sarah] really wanted was a gala dinner,” she added, saying that while they are reuniting, there is more they want to do. The singer revealed details of A Race For Life For Sarah, which is set to go ahead on July 24 at 11.30am in London's Hyde Park. Cheryl continued: “I know so many of you wanted to support her, you were helping her all the way through the illness and we’d really love it if you could join us there.” Kimberley also posted on Instagram to share the event, saying: "It’s a 5k race you can run or walk and if you can’t be in London on this date you can take part remotely from wherever you are. “It’s an amazing opportunity to come together and celebrate [Sarah’s] life and also make a huge contribution to the future outcomes of those affected by cancer.” Adding to this, Nicola said: “Let’s come together and make it a beautiful day for and contribute towards making a difference for other women too.” Sarah sadly passed away back in September of last year at the age of 29, a year after she was diagnosed with advanced breast cancer.