Involved in the apoptotic response after nerve growth factor (NGF) binding in neuronal cells. Inhibits cell cycle progression, and facilitates NGFR-mediated apoptosis. May act as a regulator of the function of DLX family members. May enhance ubiquitin ligase activity of RING-type zinc finger-containing E3 ubiquitin-protein ligases. Proposed to act through recruitment and/or stabilization of the Ubl- conjugating enzyme (E2) at the E3:substrate complex. Plays a role in the circadian rhythm regulation. May act as RORA co-regulator, modulating the expression of core clock genes such as BMAL1 and NFIL3, induced, or NR1D1, repressed. . This is the function of Ensembl gene identifier ENSG00000179222 (MAGED1, MAGE family member D1).