University of Iowa researchers are believed to be the first to capture, in real time, the movements of cancerous breast tissue cells as they form tumors. And what they saw could lead to a better understanding not only of these cells but of the antibodies that can eliminate them.

The researchers, who have published their findings in the American Journal of Cancer Research and PLOS One, discovered that cancerous cells actively pull healthy cells into tumors, according to a press release.

Moreover, just 5 percent of cancerous cells are required to form a tumor, a previously unknown figure. "It's not like things are sticking to each other," researcher David Soll says.

"These cells go out and actively recruit." Researchers found that individual cancer cells—such as those from lung, skin, and brain cancers—extend themselves outward in search of other cells.

Upon finding one, "it latches and pulls it in," adding to the size of a tumor. "No one had a clue that there were specialized cells in this process," Soll says.

"The tumorigenic cells know what they’re doing. They make tumors." But how do they know what to do? Or as Red Orbit frames it, "as evil as cancer seems to all of us, there must be a reason for the behavior that goes beyond malicious intent." Observing the cancerous cells recruiting healthy ones offers a "surprising clue" into the how part of the question, notes Medical News Today.

As for the why, Soll's hypothesis is that the cells are harking back to when they were programmed to form embryos—they may be trying to create a "self-sustaining" environment in which a tumor can grow and thrive.

"You might want one big tumor capable of producing the tissue it needs to form a micro-environment," he says. "It’s as if it’s building its own defenses against the body’s efforts to defeat them.” (In troubling news, more young people are getting a particularly nasty form of cancer.)

This article originally appeared on Newser: Real-Time Video Reveals How Tumors Form

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