This study investigated the effects of a 12-nm DMSA-coated magnetite nanoparticle (FeNP) on the gene expression profiles of two human cell lines, THP-1 and HepG2.The gene expression profiles of cells treated with 0, 50, and 100 μg/mL of FeNPs for 24 h were detected.As a result, hundreds of differentially expressed genes (DEGs) were identified in two cell lines under each treatment (Fig.1).In comparison, besides of a few DEGs concurrent in two cells, most DEGs are distinct in two cells (Fig.2), indicating the pronounced cell type-specific effects but a few cell type-nonspecific effects of FeNPs.The function annotation also revealed many cell type-specific effects but a few cell type-nonspecific effects of FeNPs.The FeNPs strongly elicited various responses in THP-1, but mainly affected metabolic processes in HepG2 (Fig.3).