Keratinocytes

Keratinocytes are the predominant cell type in the epidermis (the outermost skin layer). They originate from basal layer stem cells and undergo a process of terminal differentiation as they move outward, producing keratin intermediate filaments. In the stratum corneum, they become anucleate corneocytes, forming a tough, waterproof barrier that protects against mechanical injury, water loss, and microbial invasion.