Researchers have long studied the coat color patterns of an array of animals. One of these many animals is the cat. Researchers like Dr. Gregory Brash decided to take it upon themselves to study the coat patterns and colors of domestic cats. They found that there was development in fetal cats for coat color and pattern long before there would ever be hair. They called this "prepattern" a pattern set in the skin that would later correlate to stripes or spots. The stage this happens in is referred to as "embellishment," the body creates thicker skin where darker hair will appear later and thinner skin where the lighter color will appear later. Through further study, there were able to find a gene called DKK4. This gene was found in the thickened skin but not the thinner skinned areas. They found that there could be mutations of this gene which coded very differently for the color pattern of the cat. Brash concludes by explaining although they have found this DKK4 gene and know it interacts with a specific group of proteins known as WNTs, it is still unclear how the DKK4 gene can "remember" the target coat color it produces.