[7] During embryonic development, the epidermis develops alternating thick and thin (in terms of depth, not width) regions, previously found to match the striped mackerel or blotchy patterns that would be expressed based on mutations in the embryos' Transmembrane aminopeptidase Q (Taqpep) gene.

The genes DKK4 and Wingless Inhibitory Factor 1 (WIF1) both secrete Wnt signaling inhibitors, but in cells where both are upregulated, DKK4 produces much more of its protein than WIF1.

[6] DKK4 was also examined in specifically Abyssinian cats, which are known for their “ticked” fur with bands of colors on each hair.

Two variants, or alleles, of DKK4, p.Ala18Val and p.Cys63Tyr, were discovered in cats with obscured tabby markings.

These variants caused loss of function of the DKK4 gene[6] and smaller, more tightly packed dark areas.