Adult epidermis is maintained by self-renewing stem cells, which reside in distinct locations and give rise to progeny that differentiate along the lineages of the hair follicle, sebaceous gland, sweat gland and interfollicular epidermis. Under homeostatic conditions each stem cell population produces the differentiating cells that are appropriate for its specific location. However, in response to injury or genetic manipulation, stem cells in any region of the epidermis can give rise to all differentiated epidermal lineages. My lab is interested in the role of interactions between epidermal cells and their environment in regulating stem cell behaviour. I will present recent data on reciprocal signalling between epidermal cells, fibroblasts, adipocytes and immune cells in healthy and diseased skin. I will also discuss the different fibroblast lineages present in the dermis and how they respond to epidermal tumour formation.