Abstract
UBASH3A, also known as TULA or STS-2, is a lymphoid protein that has recently emerged as a novel regulator of T-cell activation and function. It used to be discussed as a member of the UBASH3/TULA/STS family to study the unique triple domain structure and protein‒protein interactions. In this review, we focus on the multifaceted regulatory roles of UBASH3A in biological processes within T cells. Furthermore, genetic variants in UBASH3A have been linked to at least five autoimmune phenotypes. Therefore, a broader understanding of the regulatory effects of UBASH3A in innate immunity and adaptive immunity could enable further improvements in the treatment of autoimmune disorders, antimicrobial therapy, and cancer immunotherapy.