May serve as a docking site in the receptor-mediated import of substrates across the nuclear pore complex (By similarity). Plays a role in apoptosis by tethering caspase ced-3 to the nuclear membrane preventing its autoprocessing in absence of ced-4. Interacts with caspase ced-3 (via propeptide); the interaction tethers ced-3 to the nuclear membrane and prevents its autoprocessing in absence of ced-4. Cytoplasmic side of the nuclear pore complex (By similarity). Co-localizes with caspase ced-3 to the perinuclear region in germ cells. RNAi-mediated knockdown causes no visible phenotype (PubMed:12937276). Simultaneous knockdown of npp-2 results in embryonic lethality (PubMed:12937276). RNAi-mediated knockdown in a ced-1 (e1735) and ced-3 (n718) double mutant background partially restores embryonic cell apoptosis (PubMed:27723735).