This gene encodes a member of the testis-specific serine/threonine kinase family. The encoded protein is thought to be involved in spermatogenesis via stimulation of the CREB/CRE responsive pathway through phosphorylation of the cAMP responsive element binding protein transcription factor. Alternative splicing results in multiple transcript variants.Synonyms: C14orf20, STK22E, Serine/threonine-protein kinase 22E, TSK-4, TSSK-4, TSSK5, Testis-specific kinase 4, Testis-specific serine/threonine-protein kinase 4