This Fourth of July weekend, we celebrate America's independence, and remember our forefathers, who envisioned a country in which anyone—with hard work and tenacity—could achieve anything they set their minds to.

This weekend, I will also remember three exemplars of this American toughness and achievement: coach Pat Summitt, who died last week from Alzheimer's disease; champion Muhammed Ali, who died in June from Parkinson's disease; and baseball great Lou Gehrig, who gave his memorable farewell speech after being diagnosed with ALS on July 4,1939. These three American heroes’ early deaths from the closely related brain diseases Alzheimer’s, Parkinson’s, and ALS must spur our nation to action. These diseases, collectively known as neurodegenerative diseases, are fatal, untreatable, and taking America by storm.

Neurodegenerative diseases comprise the largest unmet global health crisis of our time. And it’s getting worse. In fact, unless we do something, by 2025, 1 in 25 Americans will have been diagnosed with Alzheimer’s, Parkinson’s, or ALS. If we do not stop these diseases, by 2050 our nation will buckle under the weight of the estimated $1.1 trillion in public costs associated with caring for the projected 15 million Americans with these disastrous brain diseases. You or someone you love will be struck down.

Summitt, Ali, and Gehrig lived and breathed American strength and perseverance. Summitt led the Tennessee Lady Vols to 1098 victories as the winningest coach in Division 1 college basketball history...Ali was a three-time heavyweight boxing champion and Olympic gold medalist...Gehrig played 2130 consecutive games over his 14 years as a Yankee and earned the nickname "The Iron Horse" for his fortitude. And yet they, and innumerable tough, independent Americans just like them, were killed before their time by their brains gone awry.

In 2016, the age of Viagra and Snapchat, it is inexcusable, and downright un-American, that every day millions of Americans lose their freedom—their inalienable abilities to move, speak, swallow, and remember—to neurodegenerative diseases. Summitt, Ali, and Gehrig all waged war on their diseases, raising critical awareness and funds to battle these scourges. And now, to stop them once and for all, we must pick up where our heroes left off.

There is good news: through cutting-edge, aggressive science, we are learning more about the brain. Leading researchers now agree that Alzheimer’s, Parkinson’s, and ALS share key cellular death-and-rescue pathways. “Dramatic progress in human genetics has identified abnormalities shared by patients with ALS, Parkinson’s and Alzheimer’s,” says Tom Maniatis, PhD, the Isidore Edelman Professor of Biochemistry and Molecular Biophysics at Columbia University. “This knowledge may lead to the development of drugs capable of treating all three.” Science is coming closer to understanding—and stopping—these diseases, but until we can effectively treat them, we have to redouble our efforts.

Every single American will be affected; we must fight as one. During this election season, each and every one of us must tell both Republican and Democratic candidates—from local officials to Presidential hopefuls—that America needs a plan to stop neurodegenerative diseases, and that we demand their action. In this pivotal moment, we must support crucial research, through dollars, community events, and social media. We can stop these diseases—but we must raise an army.

Summitt, Ali, and Gehrig were powerful generals in their artistry, achievements, and activism. This weekend and every other weekend, let’s take their lead in a fight for our lives that, together, we can win. 

Meredith Estess is President of Project A.L.S. Find the organization on Facebook and Twitter.