Which layer does keratinocytes begin to die?

Keratinocytes begin to die in the stratum granulosum, which is the third layer of the epidermis. In this layer, keratinocytes undergo a process called keratinization, where they lose their nuclei and organelles as they produce keratin and accumulate lipid-rich granules. This process contributes to the formation of the skin's protective barrier. Ultimately, the dead keratinocytes are shed from the surface of the skin in the outermost layer, the stratum corneum.