May be a signaling adapter molecule involved in NGFR/p75NTR- mediated apoptosis induced by NGF. Plays a role in zinc-triggered neuronal death. In absence of reductive stress, acts as a pseudosubstrate for the CRL2(FEM1B) complex: associates with FEM1B via zinc, thereby preventing association between FEM1B and its substrates. . This is the function of BEX3 (brain expressed X-linked 3, Ensembl gene identifier ENSG00000166681).