Illumina, the world’s biggest gene sequencing company, announced plans to buy cancer detection start-up Grail for $8bn while the biotech boom was in full swing. To Illumina, Grail looked like a potential gold mine. Until reality — and regulators — entered the picture. Three years and an activist investor campaign waged by Carl Icahn later, the FT’s US pharmaceutical correspondent Jamie Smyth explains the problems that have cropped up and what it means for both companies and their shareholders.
