Background Laryngeal carcinoma is a common malignant tumor of the upper respiratory tract,and in 95% of cases thetumor is laryngeal squamous cell carcinoma (LSCC).The abnormity of SH3-domain GRB2-1ike 2 (SH3GL2) gene wasfound in LSCC.In order to clarify the relationship between SH3GL2 gene and LSCC,we evaluated the expression of theSH3GL2 gene in LSCC.Method Real-time PCR,immunohistochemistry and Western blotting were used to detect the mRNA and proteinexpression and find the various rules of SH3GL2 gene in LSCC.Results The result of real-time PCR showed that the expression level of SH3GL2 mRNA in LSCC tissue wasapparently down-regulated;immunohistochemical analysis showed that SH3GL2 protein was mainly located incytoplasm,the rate of positive cells and SH3GL2 protein expression level were fluctuated with the pathologicalclassification of LSCC;the result of Western blotting showed that SH3GL2 protein was down-regulated significantly inLSCC samples,especially in metastatic lymph nodes.Conclusions These results suggest that SH3GL2 is a LSCC related gene and its expression level is fluctuated with thepathological classification which indicate that SH3GL2 participates in the development and progression of LSCC.And itmay be considered as a novel tumor marker to find both a new anti-oncogene and relative factors of invasion andmetastasis of laryngeal carcinoma.Chin Med J 2007;120(5):385-388 Background Laryngeal carcinoma is a common malignant tumor of the upper respiratory tract, and in 95% of cases of the tumor is laryngeal squamous cell carcinoma (LSCC). The abnormity of SH3-domain GRB2-1ike 2 (SH3GL2) gene was found in LSCC. to clarify the relationship between SH3GL2 gene and LSCC, we evaluated the expression of the SH3GL2 gene in LSCC. Method Real-time PCR, immunohistochemistry and Western blotting were used to detect the mRNA and proteinexpression and find the various rules of SH3GL2 gene in LSCC. Results The result of real-time PCR showed that the expression level of SH3GL2 mRNA was mainly located in incytoplasm, the rate of positive cells and SH3GL2 protein expression level were fluctuated with the pathological classification of LSCC; the result of Western blotting showed that SH3GL2 protein was down-regulated significantly in LSCC samples, especially in metastatic lymph nodes. C onclusions These results suggest that SH3GL2 is a LSCC related gene and its expression level is fluctuated with the pathological classification that indicate that SH3GL2 participates in the development and progression of LSCC. And it it be considered as a novel tumor marker to find both a new anti-oncogene and relative factors of invasion and metastasis of laryngeal carcinoma. Chin Med J 2007; 120 (5): 385-388