Wang et al. Journal of Experimental & Clinical Cancer Research 2012, 31:44 http://www.jeccr.com/content/31/1/44 Page 5 of 7 Figure 2 Representative photographs for CLIC1 immunostaings in glioma tissues with WHO grade IV (A, Original magnification×400) and nonneoplastic brain tissues (B, Original magnification×400). In glioma tissues, the immunostaining of CLIC1 was mainly expressed in the cytoplasm of tumor cells with brown yellow (marked by arrows). In contrast, Negative immunostaining was shown in the non-neoplastic brain tissues. Additionally, CLIC1 was not present in negative controls with non-immune IgG (Figure 1C, Original magnification×400) and in normal gastric tissues (Figure 1D, Original magnification×200). P NS NS 0.005 0.008 Discussion Similar with other human solid tumor cells, the glioma cells do not only have limitless replicative potential but also readily invade surrounding brain tissues and metastasize to other tissues, which make complete sur- gical resection practically impossible and lead to poor prognosis. Therefore, molecules involved in the aggres- sive process are potential prognostic and therapeutic markers. In the present study, our data shown for the first time that the up-regulation of CLIC1 at both mRNA and protein levels in glioma tissues compared with its expression in non-neoplastic brain tissues. Additionally, highly CLIC1 protein expression was sig- nificantly correlated with advanced WHO stage and low KPS scores, suggesting that this protein might be of clinical relevance in the aggressiveness of gliomas. Together with these findings, we also demonstrated that CLIC1 expression was a statistically significant risk factor affecting overall survival of patients with glioma and was an independent risk factor predicting short overall survival. Table 2 Association of CLIC1 protein expression in human glioma tissues with different clinicopathological features CLIC1 expression High (n, %) Low (n, %) Clinicopathological features Age <55 ≥55 Gender Male Female WHO grade I II III IV KPS <80 ≥80 No. of cases 52 76 76 52 18 14 38 58 78 50 36 (69.2) 53 (69.7) 51 (67.1) 38 (73.1) 6 (33.3) 7 (50.0) 26 (68.4) 50 (86.2) 61 (78.2) 28 (56.0) 16 (30.8) 23 (30.3) 25 (32.9) 14 (26.9) 12 (66.7) 7 (50.0) 12 (31.6) 8 (13.8) 17 (21.8) 22 (44.0)