Author JK Rowling has donated £15.3 million to support multiple sclerosis research at a centre named after her late mother.
The million-pound investment by the Harry Potter author will be used at the University of Edinburgh's Anne Rowling Regenerative Neurology Clinic.
The money will be used to create new facilities at the centre and research into the treatment of MS and similar conditions.
Ms Rowling made a previous donation in 2010 and the centre, named in memory of her mother, was subsequently set up.
Anne Rowling died with MS at the age of 45.
In 2010, when Ms Rowling reached the age at which her mother died, she donated £10 million to the University of Edinburgh to found a clinic in Anne's name.
"When the Anne Rowling Clinic was first founded, none of us could have predicted the incredible progress that would be made in the field of regenerative neurology, with the clinic leading the charge," the world-renowned author said.
"I am delighted to now support the Anne Rowling Regenerative Neurology Clinic into a new phase of discovery and achievement as it realises its ambition to create a legacy of better outcomes for generations of people with MS and non-MS neurodegenerative diseases.
"It's a matter of great pride for me that the clinic has combined these lofty ambitions with practical, on the ground support and care for people with MS, regardless of stage and type - I've heard at first-hand what a difference this support can make."
The clinic is a care and research facility focusing on MS and neurological conditions with the aim of bringing more clinical studies and trials to patients.
Ms Rowling's gift will also support research projects focusing on the invisible disabilities experienced by people living with MS - such as cognitive impairment and pain.
University experts hope the donation will help have a lasting impact on people with the condition and their families.
Prof Chandran, director of the clinic, said: "Our research is shaped by listening to, and involving, individuals who are living with these tough conditions.
"The Anne Rowling Clinic's vision is to offer everyone with MS or other neurodegenerative diseases, such as MND, the opportunity to participate in a suite of clinical studies and trials.
"This incredibly far-sighted and generous donation will unlock the potential of personalised medicine for people with MS in Scotland and further afield."
Ms Rowling's series about a wizard schoolboy has won multiple awards and sold more than 500 million copies, becoming the best-selling book series in history.