Due to the increasing exposure of the skin to damaging environmental influences such as ultraviolet radiation, climatic determinants, chemicals or infections, research in this field is rapidly progressing. The interaction between the skin and the environment presents a fascinating and challenging research subject. For instance, skin aging and skin carcinogenesis are caused by both genetic and environmental factors. And also in diseases like psoriasis, atopic dermatitis and collagen diseases, genetic, immunologic and environmental factors interact. In recent years, new technologies to investigate skin response have allowed researchers to explore the interplay of environmental and genomic elements in skin cell biology, decipher the biochemical steps undertaken in the process, and study the genetics underlying variations in skin response to the environment. In this volume the state-of-the-art findings, ranging from molecular biology to epidemiology, are discussed thoroughly. The publication thus provides new insights for dermatologists, allergologists and immunologists who seek a better understanding of disease processes and new therapeutic strategies.