Fig. 5From: Prognostic value of neuron-specific enolase for small cell lung cancer: a systematic review and meta-analysisFunnel plot after trim and fill method. The small circles on the plot refer to the 16 studies included in the meta-analysis for correlation between serum NSE and OS, while the small diamonds on the plot refer to the 5 hypothetic studies needed to trim the plot to make it symmetricBack to article page