The function of SPDEF (SAM pointed domain containing ETS transcription factor, Ensembl gene identifier ENSG00000124664) is as follows. May function as an androgen-independent transactivator of the prostate-specific antigen (PSA) promoter. Binds to 5'-GGAT-3' DNA sequences. May play a role in the regulation of the prostate gland and/or prostate cancer development. Acts as a transcriptional activator for SERPINB5 promoter. .