giving scars their uneven texture. Over time, the fibroblasts continue to crawl around the matrix, adjusting more fibers and, in the process, the scarring settles and becomes stiff. This fibroblast proliferation also contracts the tissue. In unwounded tissue, these fibers are not overexpressed with thick collagen and do not contract.

EPF and ENF fibroblasts have been genetically traced with the Engrailed-1 genetic marker. EPFs are the primary contributors to all fibrotic outcomes after wounding.