Andrew Ewald is not a typical cancer researcher. He trained as a physicist and began using actual cancer cells in a three-dimensional medium to study how cancer spreads instead of looking at two-dimensional surfaces. A profile of Ewald in Johns Hopkins Magazine explains that his research eventually led him to identify the protein that makes cancer cells into pioneering leaders. Even more surprising, his team found that “at least 97 percent of new tumors” in an experiment of metastasis started from clumps of cells that traveled together instead of lone pioneers.

Individual cells, like individual people, do some things better and other things worse, depending on the genes and molecules that are active in them. The cells out in front may be great at pushing through collagen and into the bloodstream, for example, but they might be comparatively poor colonizers. Building new tumors after settling into a new organ is where the follower cells might show their strength.

Unless you think a new Chick-fil-A in New York is a “creepy infiltration,” you might not be ready to compare metastatic cancer with church planting, but Tim Keller’s description, in an interview with Philanthropy Magazine, of what makes a church plant has some similarities

A church planter is basically an entrepreneur. My guess is that only 5 to 7 percent of ministers could be church planters. They could be great ministers, but they wouldn’t be good church planters because they don’t have entrepreneurial skills. And less than 1 percent of ministers have the chops to be pioneer church planters—where you start from zero, with nobody, often in a disinterested environment. Most church plants are sprouted from a cutting taken off of another church. To start without a core group is how many church plants fail.

You could make the same point about prison re-entry or many other things in society: It starts with a small community.