A life goal for many is to live to 100. But is it possible? What makes such longevity possible?

Researchers found one key element shared between centenarians. A study published in the journal eBioMedicine, Part of the LANCET Discovery Science, found that strong immune health played a huge role in fighting diseases and staying alive past 100. But these centenarians had more than just strong immunity, they had a distinct immune cell type composition that helped them reach exceptional longevity.

“The answer to what makes you live longer is a very complex one,” senior author Stefano Monti, associate professor of medicine, biostatistics, and bioinformatics at Boston University’s School of Medicine, told USA Today. “There’s multiple factors, there’s the genetics – what you inherit from a parent, there’s lifestyle, there’s luck.”

The researchers studied analyzed single-cell profiles from seven centenarians who participated in the New England Centenarian Study, one of the largest studies of long-lived individuals in North America. Researchers compared their data with publicly available single-cell datasets from 52 other people between the ages of 20-89. Their study collected the largest single-cell dataset of centenarians, according to a press release.

The findings show that this unique immune cell composition in centenarians helped fight age-related diseases, have an increased ability to recover and fend off infections, and showed that they did not follow usual trends that are typically associated with aging.

While studies with larger sample sizes are needed to further confirm these results, this study gets us one step closer to understanding longevity.

“Centenarians, and their exceptional longevity, provide a ‘blueprint’ for how we might live more productive, healthful lives,” said senior author George J. Murphy, associate professor of medicine at Boston University’s School of Medicine.