SACRAMENTO (AP) — A former California state lawmaker announced this week she is plotting her return campaign three years after a rare autoimmune disease required her to undergo a life-saving double lung transplant.

Former Republican Sen. Sharon Runner said she is taking steps to run in a special election that will be called to fill a state Senate seat in the Antelope Valley. Sen. Steve Knight is vacating the 21st District post after winning a seat in Congress.

Runner, 60, has already received endorsements from Knight and U.S. House Majority Leader Kevin McCarthy. She said she is speaking to community leaders and other potential challengers and will formally enter the race once it’s called.

“What’s truly important is that we send someone to Sacramento as quickly as possible to combat the job-killing over-regulation, over-taxation and the dangerous situation created by early release of felons by Prop 47 and realignment,” she said in a statement about recent prison sentencing changes.

Runner did not seek re-election in 2012 after undergoing the transplant procedure. She was treated for limited scleroderma, or CREST syndrome, an autoimmune condition that attacks the body’s connective tissue.

Runner served six years in the state Assembly before being elected to the then-17th Senate District, filling the seat of her husband, George Runner, who left to serve on the state Board of Equalization.