Since we published a review article on the ov-serpin/clade B serpin family including SCCA1 and SCCA2 [1], the understanding of the functions of SCCA molecules has expanded, and the usefulness of SCCA molecules, particularly SCCA2, as biomarkers for skin inflammatory diseases such as psoriasis and atopic dermatitis (AD) has emerged. This evidence concerns the gene SERPINB4 and inflammatory skin disease.