During cornification a network of keratin intermediate filaments (KIF) and filaggrin (FLG) becomes crosslinked to the cornified envelope (CE). This facilitates the collapse and flattening of cells in the outermost stratum corneum to produce squames (Dale et al. 1978, Mack et al. 1993, Candi et al. 2005, Gruber et al. 2011).