Last updated: 08 January 2015, 14:21 GMT
Stars including Benedict Cumberbatch, Sienna Miller and Damian Lewis have joined forces to film themselves performing difficult tongue-twisters in support of a 12-year-old girl whose skin blisters at the slightest touch.
Sohana Collins from London suffers from an incredibly rare genetic disorder called epidermolysis bullosa (EB). If Sohana’s skin is touched, even lightly, it reacts as if she’s been burned.
Her hands are so fragile she has to wear gloves, and all her food must be liquidised as her mouth and oesophagus are also prone to blistering.
Her mum, Sharmila Nikapota, 45, contacted Homeland actor Damien Lewis and, after learning about Sohana, he agreed to become patron of a charity in her name - The Sohana Research Fund.
As the name of her condition is quite the tongue-twister in itself, Damien had the idea to film himself stumbling over another awkward tongue-twister before nominating Sherlock star Benedict Cumberbatch to do the same.
In turn, Benedict nominated actress and model Sienna Miller, and since then BBC presenter Mishal Husain, Damien Lewis’ wife actress Helen McCrory and Emma Watson have also thrown their weight behind the campaign.