High Quality Content by WIKIPEDIA articles! Inner nuclear membrane (INM) proteins are proteins that are embedded in or associated with the inner membrane of the nuclear envelope (NE). There are about 60 INM proteins, most of which are poorly characterized with respect to structure and function. Among the few well-characterized INM proteins are lamin B receptor (LBR), the lamina-associated polypeptide 1 (LAP1), the lamina-associated polypeptide-2 (LAP2), emerin and MAN1.