Syk, short for spleen tyrosine kinase, is a non-receptor protein tyrosine kinase [3]. It is highly expressed in hematopoietic cells and plays crucial roles in multiple biological functions. It is essential in adaptive immune receptor signalling, also mediating diverse functions like cellular adhesion, innate immune recognition, osteoclast maturation, platelet activation, and vascular development [1]. It activates through C-type lectins and integrins, triggering pathways such as the CARD9-BCL-10-MALT1 pathway and the NLRP3 inflammasome [1].

Studies suggest that Syk has a role in various diseases. In autoimmune diseases like immune thrombocytopenia (ITP) and rheumatoid arthritis, as well as in hematological malignancies, Syk-signaling pathway is a potential target for treatment [2,4,9]. In high-grade serous ovarian cancer and triple-negative breast cancers, Syk promotes DNA double-strand break resection, homologous recombination, and therapeutic resistance [5]. In solid tumors, it shows a paradoxical role, acting as a tumor suppressor in some and driving tumor growth in others, and is involved in promoting immunosuppression, tumor growth, and metastasis in the tumor microenvironment [6]. In cardio-cerebrovascular diseases such as atherosclerosis, heart failure, and diabetic cardiomyopathy, Syk is implicated in disease progression [7]. Also, in Helicobacter pylori-induced gastric mucosal inflammatory responses, Syk activation leads to up-regulation of proinflammatory genes [8].

In conclusion, Syk is a key regulator in multiple biological processes and disease conditions. Its role in autoimmune diseases, hematological malignancies, solid tumors, cardio-cerebrovascular diseases, and gastric mucosal inflammation has been revealed through various studies. Understanding Syk's functions helps in developing targeted therapies for these diseases.