Fig. 2

Data Pre-processing and Differential Expression Analysis. A-B Box plot of expression distribution between GSE152293 (A) and GSE35956 (B) samples. The x-axis represents samples, and the y-axis represents gene expression values. C-D PCA reduced-dimension diagrams of GSE152293 (C) and GSE35956 (D). The x-axis and y-axis represent the two reduced dimensions, and the dots in the diagrams represent samples. Healthy samples are shown in green, and osteoporosis samples are shown in yellow. E-F Volcano plots of differentially expressed iron metabolism-related genes for GSE152293 (E) and GSE35956 (F). The x-axis represents log2 (fold change), and the y-axis represents -log10 (P-value). Each dot represents a gene. Blue are downregulated iron metabolism-related genes; red are upregulated iron metabolism-related genes; gray are genes with no significant change in expressions or genes unrelated to iron metabolism. G-H Heatmaps of differentially expressed iron metabolism-related genes for GSE152293 (G) and GSE35956 (H). The color bars at the top represent the two groups of patients. Yellow means osteoporosis samples, and green means healthy samples. The blue blocks in the diagram represent low expressions, and the red blocks represent high expressions