Receptor for egr (PubMed:12084706, PubMed:12894227). Involved in induction of apoptosis by triggering JNK signaling (PubMed:12894227). Mediates the tumor suppressor activity of egr which eliminates oncogenic cells from epithelia, thereby maintaining epithelial integrity (PubMed:19289090). Following UV-induced epidermal damage, binds to egr released from apoptotic epidermal cells and plays a role in development of thermal allodynia, a responsiveness to subthreshold thermal stimuli which are not normally perceived as noxious (PubMed:19375319). Together with Moe, involved in control of axon targeting of R8 and R2-R5 photoreceptors, independent of egr (PubMed:23544124). Interacts with egr (PubMed:12084706). Interacts with Traf6 (PubMed:12894227). Interacts with Moe (PubMed:23544124). In third instar larvae, detected in photoreceptor neurons, including R8 photoreceptors, and also in adult head (at protein level) (PubMed:23544124). Expression appears to be very low or undetectable in pregastrulating embryos. During gastrulation, detected in the inner layer of embryonic tissue corresponding to the presumptive mesoderm. At germ band extended stages, continues to accumulate in the mesodermal segments of the embryo. In later-staged embryos (stages 15/16), detected in subsets of cells within the condensing nerve cord (PubMed:12894227). Present at all stages of development with expression detected in embryo, larva, pupa and adult. 'wengen' is named after a village at the foot of the Eiger mountain after which the egr gene is named.