Fig. 4

Developmental phase-dependent gene expression analysis. A Module eigengene (ME) heatmap representation of gene expression data derived from lung samples collected at the indicated (from fetal to post-natal) developmental time-points. Median-normalized expression levels are shown on a low-to-high scale (blue–white–red). B Results of pathway enrichment analysis performed on distinct modules of co-expressed genes. Representative terms, among the most significantly enriched in one or more modules, are reported (modules 8, 9 and 10 are not shown as they are enriched only in marginally statistically significant pathways; the full list of terms and modules is available in Additional file 1). Color saturation corresponds to enrichment significance (− Log q-values). C: Correlation analysis between MEs and histomorphometry parameters (negative correlations are shown in purple and positive correlations in yellow, − Log p-values are indicated in parenthesis)