Expression of clustered miRNAs is coordinated. Shown are pairwise scatter plots of expression values for mature miRNAs transcribed from genomic regions within 50 kb of each other. (a) miR-15a, miR-15b and miR-16 transcribed from two intronic clusters at C3q26.1 (SMC4L1) and C13q14.3 (DLEU2). (b) miR-25, miR-93 and miR-106b transcribed from an intronic cluster at C7q22.1 (MCM7). (c) miR-199a, miR-199a*, miR-199b and miR-214 transcribed from one intergenic cluster at C1q24.3 and two intergenic stem-loops at C9q34.11 and C19p13.2. Pearson correlation coefficients (r) and data points shown are based on samples with available array CGH data and no identified genomic loss or gain at the relevant locus (Additional data file 1). Genome plots are drawn to scale as shown in the legend (bottom right), except where missing regions are indicated by vertical bars. Positive and negative strands are depicted by the top and bottom plots, respectively. Gene loci and miRNA stem-loop regions are colored in blue and red, respectively. The location of exons is marked by greater line width.