Our time-lapse imaging experiments showed that OPCs had abnormal morphologies and dorsalward migration movements and that axons followed abnormal trajectories within spinal cords of pes null larvae. In frogs, reduction of pes function with antisense morpholino oligonucleotides caused craniofacial defects by interfering with the migration of Echinacoside neural crest cells into the brachial arches. Pes interacts with insulin receptor substrate 1, which regulates insulin and insulin-like growth factor Lucidenic-acid-LM1 signaling, leading the authors to propose that Pes regulates cell intrinsic mechanisms necessary for neural crest migration. The disease severity can range from infrequent, localized skin affections at predeliction sites to acute exacerbation of the entire skin leading to erythrodermia requiring hospitalization. The patients suffer from significant reductions in their quality of life due to pruritus, sleeplessness and stigmatization. The pathogenesis of AD is complex. Apart from genetic factors responsible for a predisposition, several alterations of the skin immune system and stromal cells are important. Acute exacerbation of disease is characterized by a dense infiltrate of the dermis with CD4 + T cells showing a Th2-phenotype. Under more chronic conditions, the Th2 predominance is shifted towards a Th1 immune response as shown in atopy patch test experiments. Therapy of AD is based on a regular treatment with basic emollients supplemented with intermittent immunosuppressive therapy of exacerbated skin disease. Comparisons with regard to the effectiveness of blue light irradiation as compared to e.g. UV-based treatment regimens are not appropriate. The improvement observed in our patients who were selected based on their unresponsiveness to classical interval therapy with class II-III topical corticosteroids may thus be comparable to that of classically used UVA1 irradiation. However, improvement of long term disease control and not the ability to provide rapid, acute intervention for disease exacerbation may be the main feature of blue light therapy. The overall effectiveness of UV treatment on AD is well accepted.