WW domain-containing transcription regulator protein 1 (WWTR1[5]), also known as Transcriptional coactivator with PDZ-binding motif (TAZ), is a protein that in humans is encoded by the WWTR1gene. WWTR1 acts as a transcriptional coregulator and has no effect on transcription alone.[5] When in complex with transcription factor binding partners, WWTR1 helps promote gene expression in pathways associated with development, cell growth and survival, and inhibiting apoptosis.[6] Aberrant WWTR1 function has been implicated for its role in driving cancers.[7][8][9] WWTR1 is often referred to as TAZ due to its initial characterization with the name TAZ. However, WWTR1 (TAZ) is not to be confused with the protein tafazzin, which originally held the official gene symbol TAZ, and is now TAFAZZIN.