Abstract: Sab (SH3 domain-binding protein that preferentially associates with Btk) that is also called SH3BP5 (SH3 domain-binding protein 5), is a scaffold protein on mitochondrial outer membrane in the modulation of mitochondrial function. Sab not only combines with the tyrosine kinase Btk (Bruton's tyrosine kinase), but also binds to the serine threonine kinase JNKs (c-Jun amino-terminal kinases) and p38γ. Thus Sab can regulate B cell antigen receptor, mitochondrial JNK and p38γ signaling pathway, which is associated with the critical physiological function, such as B-cell development and differentiation and regulation of mitochondrial signaling transcription. Inhibition or induction on the expression of Sab can ameliorate the diseases arising from the abnormal level of Btk, JNKs and p38γ, such as nervous system diseases and liver injury. Therefore, Sab could be expected as a new target for drug development. In this article, we provide an overview of the structure and functions of Sab and its relationship to diseases of diffuse large B-cell lymphoma, nervous system diseases and liver injury, aiming to provide new ideas and theoretical basis for the development of new drugs.