Synthetic multivulva (synMuv) class A protein (PubMed:7982579, PubMed:8054684). SynMuv proteins are required to repress the induction of vulval development (PubMed:7982579, PubMed:8054684). Acts redundantly with SynMuv class B protein lin-15B, and lin-35 to negatively regulate vulval development, most likely through antagonization of the Ras-signaling pathway (PubMed:8054684, PubMed:16624904). May also negatively regulate vulval development in association with other SynMuv class B proteins such as dpl-1 and efl-1 (PubMed:11463372). Regulates let-23 basal activity (PubMed:8054684). Required for the correct expression and/or stability of lin-56 (PubMed:21196525). Greatly reduced nuclear accumulation of lin-56 protein and increased mRNA levels (PubMed:21196525). No obvious vulval development defects (PubMed:8054684, PubMed:11463372). Double knockout with the synthetic multivulva class B protein lin-15B, dpl-1, efl-1 or lin-35 results in a multiple vulva (Muv) phenotype (PubMed:8054684, PubMed:11463372, PubMed:16624904). The proteins lin-15A and lin-15B are produced from a single precursor mRNA with non-overlapping transcripts where lin-15B is the upstream transcript and lin-15A is the downstream one. The precursor mRNA is cleaved at the polyadenylation site and a 22-nucleotide SL2 leader sequence is trans-spliced to the 5'-end of lin-15A to allow its translation.