However, UV is one of the main risk factors for the development of epidermal or melanocytic skin tumors. Thus, the development of UV-free irradiations with proven therapeutic effect is beneficial. All patients Sipeimine included in the present study were suffering from long-lasting AD with no response to standard interval treatment using topical class II-IV corticosteroid application. Thus, blue light treatment can be considered an ����add on���� therapy as compared to their prior treatment protocol. However, the contribution of the combinatory therapeutic approach to the overall efficacy of the treatment needs to be evaluated further. Due to the non-interventional, observational nature of the present study, not all patients agreed to complete all questionnaires and came to follow up assessments. Because of the study design, patients were usually re-evaluated when they experienced a flare up just before they received another cycle of irradiation, so the assessments may in some cases underestimate the overall clinical response. In addition, since treatment cycles are offered only when disease worsening is observed, not all patients received the same amount of irradiation. To better estimate the degree of response in relation to established therapies such as other Cantharidin UV-light treatments, clinical trials with proper control groups need to be conducted. Using skin biopsies and serological analyses, we have started to investigate the mechanism of action of blue light irradiation in AD. Similar to other treatment modalities, a visible effect of this treatment on serum parameters was not obvious. As described previously, despite the observation that a certain Th1/Th2 ratio in the skin correlates with disease severity, serum levels of pro- and anti-inflammatory cytokines were low and no significant changes observed. Serum TARC was elevated in our AD patient collective prior to the study as reported, but alterations were not achieved by therapy. The blue light-mediated alterations in the inflammatory infiltrate of the skin involved the absence of signs of lymphocyte or DC/LC apoptosis. Thus, a strongly reduced frequency of the first cleavage of zygotes and a complete developmental block at the two-cell stage account for infertility of females lacking importin a7.