Serpins are the largest and most diverse family of serine protease inhibitors which are involved in a number of fundamental biological processes such as blood coagulation, complement activation, fibrinolysis, angiogenesis, inflammation and tumor suppression and are expressed in a cell-specific manner. Serpins are a group of proteins with similar structures that were first identified as a set of proteins able to inhibit proteases. The acronym serpin was originally coined because many serpins inhibit chymotrypsin-like serine proteases (serine protease inhibitors). Over 1000 serpins have been identified. Mouse SerpinB10, also known as Peptidase inhibitor 10, PI-10, Bomapin and SERPINB10, is a nucleus and cytoplasm protein which belongs to the serpin family and Ov-serpin subfamily. SerpinB10 is expressed specifically in the bone marrow. SerpinB10 is a protease inhibitor that may play a role in the regulation of protease activities during hematopoiesis and apoptosis induced by TNF. SerpinB10 is a redox-sensitive nuclear serpin that augments proliferation or apoptosis of leukaemia cells, depending on growth factors availability. SerpinB10 may regulate protease activities in the cytoplasm and in the nucleus.