The epidermis is divided into five layers. From outside to inside (dermis). The stem cells are located in the stratum basale and migrate outwards in their differentiation process

1. Stratum corneum: The outmost layer, made of dead keratinocytes with a layer of protein around them (they have undergone keratinization)
2. Stratum lucidum: Also dead keratinocytes (there is no real distinction here other than that the poor keratinocytes have died but have not finished the keratinization process)
3. Stratum granulosum: the keratinocytes are still on the move, by this point they have kertahyalin granules
4. Stratum spinosum: the keratinocytes migrating up, they have nice oval nuclei
5. Stratum basale: Single layer of proliferating columnar keratinocytes, melanocytes (pigmented cells) and Merkel cells (mechanoreceptors) also live here

Of note, Langerhans cells, which are specialized antigen-presenting cells are present in all layers of the epidermis but are mostly in the stratum spinosum.