FGR and graft versus host disease: Based on system biology and network-based analyses of the differentially expressed whole-transcriptome, this study not only confirmed that the differentially expressed genes of FGR at the whole-transcriptome level are significantly enriched in metabolism and neural and cardiac systems but also elucidated the critical correlation between the differentially expressed transcriptome and immune system diseases, such as Graft-versus-host disease and systemic lupus erythematosus.