This is the reason that in countries with poor sanitation, human skin is exposed to E. coli strains from faecal matter but it does not usually result in an infection.

[5] S100A7 is highly homologous to S100A7A (koebnerisin) but distinct in expression, tissue distribution and function.

[6][7][8][9] This protein is markedly over-expressed in the skin lesions of psoriatic patients, but is excluded as a candidate gene for familial psoriasis susceptibility.

[4] The expression of psoriasin is induced in skin wounds[10] through activation of the epidermal growth factor receptor.

[14] S100A7 interacts with RAGE (receptor of advanced glycated end products).