The protein encoded by this gene is coordinately expressed with activator of cAMP-responsive element modulator (CREM). It is associated with CREM and confers a powerful transcriptional activation function. CREM acts as a transcription factor essential for the differentiation of spermatids into mature spermatozoa. There are multiple polyadenylation sites found in this gene. Alternative splicing results in multiple transcript variants encoding the same protein.