['The metastasis suppressor 1 (MTSS1) is a newly discovered protein putatively involved in tumour progression and metastasis.', 'Immunohistochemical expression of MTSS1 was analysed in 264 non-small-cell lung carcinomas (NSCLCs).', 'The metastasis suppressor 1 was significantly overexpressed in NSCLC compared with normal lung (P=0.01). Within NSCLC, MTSS1 expression was inversely correlated with pT-stage (P=0.019) and histological grading (P<0.001). NSCLC with MTSS1 downregulation (<20%) showed a significantly worse outcome (P=0.007). This proved to be an independent prognostic factor in squamous cell carcinomas (SCCs; P=0.041), especially in early cancer stages (P=0.006).'] Is downregulation of MTSS1 expression an independent prognosticator in squamous cell carcinoma of the lung?