Malpighian layer
The Malpighian layer of the epidermis is generally defined as both the stratum basale and the thicker stratum spinosum immediately above it as a single unit, although it is occasionally defined as the stratum basale specifically, or the stratum spinosum specifically.
It is named after the Italian biologist and physician Marcello Malpighi.
Basal [cell carcinoma] originates from the basal layer of the stratum malpighii.
This layer is where almost all of the mitotic activity in the epidermis occurs. The activity of these cells is increased by IL-1 and epidermal [growth factor]. The activity is decreased by transforming [growth factor beta].