X-linked ectodysplasin-A2 receptor (XEDAR) is a recently isolated member of the tumor necrosis factor receptor family that is highly expressed during embryonic development and binds to ectodysplatin-A2 (EDA-A2) (1). Two predominantly expressed isoforms, XEDAR-s and XEDAR-L, differ by only a 21-amino region at the juxtamembrane region of the cytoplasmic domain. Neither isoform possesses a death domain and both have been shown to act mainly through TRAF3 and TRAF6 to activate the NF-kappaB and JNK pathways (2). Cells transfected with XEDAR and treated with EDA-A2 cause the assembly of a secondary complex containing FADD, caspase-8 and caspase-10, leading to the activation caspase-8 and caspase-3, and finally apoptosis (3). The EDA-A2-induced apoptosis is dependent on caspase-9 activation, as various pharmacological and genetic inhibitors of caspase-8 blocked apoptosis following EDA- A2 treatment (3). Applications: Suitable for use in Western Blot, ELISA and Immunohistochemistry. Other applications not tested. Recommended Dilutions: Western Blot: 0.5-2ug/ml Immunohistochemistry (paraffin): 10ug/ml Optimal dilutions to be determined by the researcher. Positive Control: HEK293 Cell Lysate, Human Skin Tissue Lysate, Human Skin Tissue Slide Storage and Stability: May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20C. Aliquots are stable for 12 months after receipt. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.