Involved in repression of vulval fate, possibly by a tumor suppressor protein Rb-mediated mechanism (PubMed:10880475, PubMed:16890929). May act in a common pathway with retinoblastoma-like protein homolog lin-35 and hpl-2 to influence the ER stress response in the intestine (PubMed:24715729). Plays a role in recruiting chromobox protein homolog hpl-2 to specific chromatin sites (PubMed:16890929). Interacts (via PLVPV motif) with chromobox protein homolog hpl-2 (via chromo (shadow subtype) domain); the interaction is direct and influences localization of hpl-2 to nuclear foci. Localization to nuclear foci overlaps partially with chromobox protein homolog hpl-2. In the L3 stage, expressed in syncytial hypodermal cell 7, body wall muscles, intestinal cells, distal tip cells and many neurons. Expressed both maternally and zygotically. RNAi-mediated knockdown causes various defects, including sterility, multiple vulvae, protruding vulva and arrested larvae (PubMed:10880475). Abolishes many hpl-2 nuclear foci (PubMed:16890929). Causes ectopic up-regulation of transcription of specific genes, such as lin-39 and lag-2 (PubMed:16890929).