Ni B, et al. - By screening the online electronic databases of PubMed, Embase, and the China National Knowledge Infrastructure, a comprehensive literature search was conducted to examine the relationship between spleen tyrosine kinase (SYK) expression and clinical outcomes in patients with solid tumors. The findings from the present study suggested that under-expression of SYK might be a predictive biomarker for poor prognosis in breast cancer and hepatocellular carcinoma patients.