The pigeon epidermal differentiation complex. The pigeon EDC is located on (A) scaffolds 1246 and (B) 683 of the draft pigeon genome. It is bound by nicastrin and cathepsin S, and contains putative genes for the cornified envelope precursors repetin, cornulin, involucrin and filaggrin. In addition, the S100 genes S100A11, S100A4 and two copies of S100A9 are present. Two putative keratin-associated proteins (KAPs) are present, and clusters of beta keratins, feather keratins, scale keratins and claw keratins.