Iron Man star Robert Downey Jr gave young patients a dose of Hollywood on a visit to Great Ormond Street Hospital.
The actor dropped by the central London paediatric centre's cancer ward ahead of the European premiere of Captain America: Civil War in London on Tuesday.
He spent Monday afternoon visiting patients and their families including seven-year-old Ethan Miller, who suffers from the rare blood disease ITP as well as type 1 diabetes.
His father Lee said: "Ethan has been in and out of hospital a lot in the past three years. He watches the films all the time and virtually lives in his Iron Man costume.
"Ethan was over the moon to meet his hero and it has really helped to lift his spirits."
The two posed together in the hospital chapel, with Ethan wearing his Iron Man costume.
Downey has played Tony Stark - otherwise known as Iron Man - since 2008.
Great Ormond Street is one of the world's leading children's units, treating young patients with rare, complex and life-threatening conditions.
The visit was organised by Disney officials, who have worked with the hospital's charity since 2008, raising more than £10 million for the unit's redevelopment.
The Evening Standard recently helped to raise more than £3.5 million for the hospital as part of its Give to GOSH appeal which ended in February.
Additional reporting by PA
