Human casein is an orally active phosphoprotein that can be separated into various electrophoretic components such as α2-Casein, κ-Casein, β-casein, and γ-casein. It can be combined and grafted with other polymers, cross-linkers, or monomers to enhance its functionality. Human casein promotes calcium absorption, reduces the incidence of fissures and smooth surface caries, and fosters the proliferation of prostate cancer. Additionally, it finds diverse applications in the paper, leather, textile, and food industries as a coating, adhesive, and packaging material.