S100A9 and dermatophytosis: A genome-wide association (GWAS) study of 10 Persian cats with severe dermatophytosis (n = 8) or DPM (n = 2) and 16 control cats without dermatophytosis showed affected cats had a highly divergent haplotype for the S100A9 gene, which encodes for a subunit of the antimicrobial peptide calprotectin, with 13/135 differences in amino acids (30).