Sens. Susan Collins (R-ME) and Amy Klobuchar (D-MN) and 10 other senators, in a bipartisan letter Friday, urged President Donald Trump to increase current funding for Alzheimer’s disease research in his fiscal year 2018 budget request.

“In addition to the human suffering it causes, Alzheimer’s is our nation’s most expensive disease, costing the United States more than $236 billion a year, including $160 billion in costs to Medicare and Medicaid,” they wrote. “These costs will skyrocket as the baby boom generation ages.”

The senators also asked Trump to support efforts to meet the research investment objective set forth in the National Plan to Address Alzheimer’s Disease, which calls for a way to prevent and treat Alzheimer’s by 2025. To meet this goal, the senators noted, experts say that $2 billion annually in Alzheimer’s research funding is needed.

Collins and Klobuchar noted the $350 million increase for Alzheimer’s research funding — the largest increase for Alzheimer’s research funding in history — provided via the Consolidated Appropriations Act of 2016. They also noted that the 21st Century Cures Act provides additional funding for the BRAIN Initiative and creates the EUREKA prize competition to address diseases, including Alzheimer’s.

“These are critical achievements, but we need to do more,” they wrote.

The letter also was signed by Sens. John Boozman (R-AR), Bob Casey (D-PA), Bill Cassidy (R-LA), Ed Markey (D-MA), Sen. Jerry Moran (R-KS), Debbie Stabenow (D-MI), Thom Tillis (R-NC), Mark Warner (D-VA), Sheldon Whitehouse (D-RI) and Roger Wicker (R-MS).