Two years after launching, Cerebral had become a star in the telemedicine business space. The company had attracted tens of thousands of patients and was valued at close to $5 billion. CEO Kyle Robertson had big plans for the startup, but this spring, those plans started to crumble. WSJ’s Rolfe Winker and Khadeeja Safdar started reporting on Cerebral. Their reporting would lead to federal investigations and major changes for the company.