September is Prostate Cancer Awareness Month, the most common cancer in men, after skin cancer. Humans are living longer than ever before, leading to inevitably higher rates of cancer worldwide. In the next 20 years, the World Health Organization expects to see a 57 percent increase in cancer diagnosis, pushing the need for spreading awareness into the forefront of medicine.

The Blue Cure Foundation, a non-profit dedicated to improving prostate cancer prevention and treatment through advocacy, has made a nationwide request to the mayors of America’s major cities to light a city landmark blue for an evening in September. New York City’s Mayor Bill de Blasio, Los Angeles’ Mayor Eric Garcetti, Chicago’s Mayor Rahm Emanuel, and Philadelphia’s Mayor Michael Nutter are some of those respectfully called upon to support the “Light it Blue” campaign.

Prostate cancer occurs in a male’s reproductive system. The prostate, a small walnut-shaped gland that produces seminal fluid, is responsible for nourishing and transporting sperm. One out of every seven men in the United States will be diagnosed with prostate cancer in 2015, adding to the nearly three million American men currently living with the disease. The cancer cells usually grow very slowly, and occur most often in men older than 65 years and older, according to the National Cancer Institute.

It was in 1999 that the American Foundation for Urological Disease designated September as Prostate Cancer Awareness Month, with heightened focus on making the public better informed about prostate health. Every year since, health expert, advocates, and individuals affected by prostate cancer rally together to spread awareness and encourage prostate screenings, educate young men about risk factors and symptoms, and advocate for research funds.