CPEB2 is highly similar to cytoplasmic polyadenylation element binding protein (CPEB), an mRNA-binding protein that regulates cytoplasmic polyadenylation of mRNA as a trans factor in oogenesis and spermatogenesis. Studies of the similar gene in mice suggested a possible role of this protein in transcriptionally inactive haploid spermatids.The protein encoded by this gene is highly similar to cytoplasmic polyadenylation element binding protein (CPEB), an mRNA-binding protein that regulates cytoplasmic polyadenylation of mRNA as a trans factor in oogenesis and spermatogenesis. Studies of the similar gene in mice suggested a possible role of this protein in transcriptionally inactive haploid spermatids. Alternatively spliced transcript variants encoding distinct isoforms have been described.