The death has occurred of the vice-chancellor of Queen's University, Belfast, Professor Patrick Johnston, the college confirmed on Sunday.
A leading cancer expert Prof Johnston took over as president and vice-chancellor of Queen’s University in 2014 stating that his ambition was to make the college an “international powerhouse”.
Prof Johnston, who was born in 1958 was recognised as one of the world’s top cancer researchers. He died suddenly on Sunday.
In a statement on Sunday Queen’s University said it was with a “deep sense of shock and loss” that it had to announce the “untimely and sudden death” of Prof Johnston.
“We extend our deepest sympathies and condolences to Iseult, his wife, and their four boys, Seamus, Eoghan, Niall and Ruairi and the wider family circle at this desperately sad time,” said the college’s registrar and chief operating officer James O’Kane.
Prof Johnston was educated at St Columb’s College, Derry and University College, Dublin, where he gained a degree in Medicine in 1982.
In 1987 he obtained a Fellowship at the National Cancer Institute at Bethesda, Maryland, in the US where he began further clinical training in medical oncology.
He joined Queen's in 1996 as Professor of Oncology and was centrally involved in the establishment of the Centre for Cancer Research and Cell Biology which has been described as having "revolutionised cancer treatment in Northern Ireland and further afield".
His research focus was on the understanding of mechanisms of drug resistance to therapeutic agents. This resulted in a number of prestigious landmark publications, more than 20 patents and the award of grants of £95 million from research and philanthropic bodies including Cancer Research UK, the Medical Research Council, Atlantic Philanthropies, the Department of Health, Social Services and Public Safety and the National Institute of Health for the centre.
The SDLP outgoing MP for South Belfast Dr Alasdair McDonnell said Prof Johnston’s death was a “terrible loss to Queen’s University, cancer research and Northern Ireland”.
He described him as a “powerful figure, working to find a cure for cancer”.
Former Sinn Féin Stormont finance Minister Mairtin O Muilleoir said he was shocked to hear of his death, and described him as a "global leader in the search for a cure for cancer".
Alliance leader Naomi Long said his death was a "huge loss to university and city" of Belfast.