This transgene comprises a genomic DNA fragment containing the coding region of the chicken lysozyme (also called hen egg lysozyme, HEL) gene joined to the 5' promoter elements of the liver-specific mouse abumin gene. The mean HEL concentration, measured by enzyme-linked immunosorbent assay (ELISA), in sera of mice of this line is 58 ng/ml; serum HEL levels in female mice are approximately twice those in males. (J:104190, J:127344, J:210801)