Walter "Walt" Hartwell White Sr. (also known by his clandestine alias Heisenberg) is a fictional character and the main protagonist of Breaking Bad, portrayed by Bryan Cranston. A graduate of the California Institute of Technology, Walt was once a promising chemist who cofounded the company Gray Matter Technologies. He left Gray Matter abruptly, selling his shares for $5,000; soon afterward, the company made a fortune of roughly $2.16 billion, much of it from his research. Walt subsequently moved to Albuquerque, New Mexico, where he became a high school chemistry teacher. After being diagnosed with Stage IIIA lung cancer, he resorts to manufacturing methamphetamine and drug dealing to ensure his family's financial security after his death. Series creator Vince Gilligan has described his goal with Walter White as "turning Mr. Chips into Scarface", and deliberately made the character less sympathetic over the course of the series. Walt's transition from mild-mannered school teacher and family man to ruthless criminal mastermind and murderer is the show's central focus.