The other end of the rainbow: infrared and skin.

Although infrared radiation (IRR) is ubiquitous in the terrestrial milieu, its effects on human skin have until now been largely ignored. Recent studies suggest an important role for infrared A (IRA) radiation (760-1440 nm) in dermal inflammation, photoaging, and photocarcinogenesis. In this issue, Calles et al. identify and analyze the IRA-induced transcriptome in human dermal fibroblasts. Their work paves the way for new research directions in IRA photobiology and raises important clinical questions regarding photoprotection and IRR-based dermatotherapy.