1. Proliferation: In the basal layer, stem cells divide to produce new keratinocytes. 2. Differentiation: As keratinocytes move up to the stratum spinosum, they start to differentiate and produce keratin. 3. Keratohyalin Granule Formation: In the stratum granulosum, keratinocytes accumulate keratohyalin granules, which are rich in proteins such as profilaggrin and loricrin. 4. Cornification: In the stratum corneum, keratinocytes become fully keratinized, forming a tough, protective outer layer. These cells lose their nuclei and organelles, becoming corneocytes. 5. Desquamation: The outermost keratinized cells are eventually shed off in a process known as desquamation.
