DPP4 and atopic eczema: A researcher found that [70] incubating peripheral blood mononuclear cells (PBMC) with peptide extracts from A1 cow milk (BCM-7) increased the gene expression of the μ-opioid receptor (MOR) while decreasing DPP4 (dipeptidyl peptidase 4) enzyme’s gene expression in children aged <14 years old with atopic dermatitis.