The foundation was founded 25 years ago in 1994 at Marilyn Simons' suggestion, and resided for five years in a file box in her dressing room. Twenty years ago, she was diagnosed with breast cancer, later surviving a second cancer diagnosis as well. She decided then to establish a more secure grounding for the philanthropy, moving the foundation into a small office with a few employees. Its growth into a multibillion-dollar philanthropy came faster and bigger than either had expected. The foundation employs a staff of 330, with plans to expand to 500 possibly by 2022. Simons said the staff would include about 300 in-house scientists, 100 staff members to focus on grants for recipients outside the organization and 100 staff for foundation operations.