Our previous study revealed that spaceflight induced biological changes in human cervical carcinoma Caski cells.Here,we report that 48A9 cells,which were subcloned from Caski cells,experienced significant growth suppression and exhibited low tumorigenic ability after spaceflight.To further understand the potential mechanism at the transcriptional level,we compared gene expression between 48A9 cells and ground control Caski cells with suppression subtractive hybridization (SSH) and reverse Northern blotting methods,and analyzed the relative gene network and molecular functions with the Ingenuity Pathways Analysis (IPA) program.We found 5 genes,SUB1,SGEF,MALAT-1,MYL6,and MT-C02,to be upregulated and identified 3 new cDNAs,termed B4,B5,and C4,in 48A9 cells.In addition,we also identified the two most significant gene networks to indicate the function of these genes using the IPA program.To our knowledge,our results show for the first time that spaceflight can reduce the growth of tumor cells,and we also provide a new model for oncogenesis study.