Long-time YouTube boss Susan Wojcicki, who played a key role in Google’s history on several occasions, died on Friday at the age of 56 from lung cancer. She had been living with the disease for two years, Google chief executive Sundar Pichai wrote in an email to employees. Wojcicki had stepped down as head of the video platform last year in order to focus on her health. The former Intel manager rented out her garage to Google’s two founders, Larry Page and Sergey Brin in 1998. She was one of the company’s first employees – and helped establish the way Google displays advertising, which is how …