The billionaire is investing $50 million of his personal money in the London-based Dementia Discovery Fund, which is a private-public collaboration that invests in innovative dementia research. He plans to invest at least another $50 million into other startups that are working on “less mainstream” approaches, but these have not yet been identified.

Alzheimer’s is the sixth leading cause of death in the U.S., and is expected to affect more than 131 million people worldwide by 2050. Despite this, there is no effective treatment to stop or slow the progression of the disease.

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Gates has called it a “huge” and “growing” problem, noting that “the scale of the tragedy—even for the people who stay alive—is very high.” While he acknowledged to Reuters that it will take “probably 10 years before new theories are tried enough times to give them a high chance of success,” Gates told CNN that he believes there is a solution. He said that “any type of treatment would be a huge advance from where we are today, but the long-term goal has got to be cure.”

Gates has spent the past year studying the science of dementia and speaking to experts in the field. Through these conversations, he identified five areas of need: understanding how Alzheimer’s progresses; detection and diagnosis; approaches to stop the disease; facilitating participation in clinical trials; and better use of data.

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This investment is the first time Gates has made a commitment to a non-communicable disease. Otherwise known as the DDF, the Dementia Discovery Fund was launched in 2015 and draws on drugmakers such as GlaxoSmithKline (GSK), Johnson & Johnson (JNJ), and Pfizer (PFE), as well as the British government. To date, the organization has invested in 12 startups that are working to address the biological processes that lead to dementia.