Fig. 1

Heat map shows relative fold change of miRNAs in bladder cancer compared with normal adjacent tissue as reported by eligible studies. Hierarchical clustering of 19 selected studies and datasets with the 49 deferentially expressed miRNAs using average linkage clustering. Here we selected 52 miRNAs (26 down-regulated miRNAs and 26 up-regulated miRNAs) which reported in at least five expression profiling studies. Every row represents an individual miRNA, and each column represents an individual dataset. Acronyms are explained in Additional file 3: Table S1 and the number of miRNAs analyzed in each study is graphically depicted on the right. Pseudocolours indicate transcript levels from low to high on a log 2 scale from −3 to 3, ranging from a low association strength (dark, black) to high (bright, red, or green). Short red and green vertical bars indicate upregulated and downregulated miRNAs, respectively. While the black bar with the pseudocolours 0 means that there is no available data reported in the primary studies