The keratinocyte is the major cell type of the epidermis, making up about 90% of epidermal cells. The epidermis is divided into four or five layers (depending on the type of skin) based on keratinocyte morphology: stratum basale (at the junction with the dermis) stratum spinosum stratum granulosum stratum lucidum (only present in thick skin - for example palms of hand and soles of feet) stratum corneum Keratinocytes originate in the basal layer from the division of keratinocyte stem cells. T… (More on Keratinocyte)