Blk, also known as B-cell lymphocyte kinase, is a member of the SRC family nonreceptor tyrosine kinase. It is involved in the B-cell receptor (BCR) signaling pathway, playing a crucial role in B cell development and function. Dysregulation of Blk is associated with autoimmune diseases and cancer [3].

BLK-deficient mice produce less inflammatory cytokines and are more resistant to death upon IL-1β challenge, indicating that BLK positively regulates TLR/IL-1R-mediated inflammatory response [1]. BLK-deficient mice also exhibit lower serum cytokine levels and higher lethality after VSV infection, suggesting that BLK is a key kinase positively modulating IRF3-dependent signaling cascades and executing an antiviral effect [4]. In addition, in R-CHOP treated diffuse large B-cell lymphoma patients, BLK expression was associated with a poor prognosis [2].

In conclusion, Blk has essential functions in B cell-related signaling pathways and antiviral responses. The study of Blk knockout mouse models has provided insights into its role in inflammatory responses, antiviral immunity, and certain cancers, highlighting its significance in understanding disease mechanisms and potentially developing new therapeutic strategies.