In Mosser Companies v. San Francisco Rent Stabilization & Arbitration Board (2015) 233 Cal.App.4th 505, Brian, the current occupant of a rent-controlled apartment on Fell Street in San Francisco, had moved into the apartment when his parents took possession of it when he was 13 years old. (Mosser Companies, supra, at p. 509.) Nine years later, after two of their three children left home, Brian's parents moved to a different location, but Brian, who was then 23 years old, stayed on in the Fell Street apartment. (Ibid.) The landlord then announced it was raising the rent from $1,681.75 to $3,295 on the theory that the "original occupants"--Brian's parents--no longer lived in the apartment. (Ibid.)