Plays a role in regulating Notch activity. Plays a role in regulating the expression of CDKN1A and several members of the Wnt pathway, probably via its effects on Notch activity. Required during embryogenesis for inner mass cell survival (By similarity). Associates with the pre-60S ribosomal particle. Interacts (via WD repeats) with uL18 (By similarity). Interacts (via UBL domain) with MDN1 (via VWFA/MIDAS domain) (By similarity). Belongs to the NLE1/RSA4 family.