Gene expression profiles of human osteosarcoma cell sublines with different pulmonary metastatic potentials. to screen the pulmonary metastasis-associated molecules of Osteosarcoma and evaluate their functions concerning prognosis prediction.cDNA microarray analysis has been applied to 2 pairs of osteosarcoma cell sublines with differential metastatic potentials to the lung. Immunohistochemistry and survival analysis have been performed to clinical samples of osteosarcoma patients.Analysis detected 484 differentially expressed genes between the high metastatic subline, F5M2, and the low metastatic subline, F4. There were 1257 genes differentially expressed between newly established high-metastatic sublines named Saos-2M2 and its parental cell line Saos-2. Furthermore, 16 commonly up-regulated genes and 5 commonly down-regulated genes were identified by clustering analysis. EREG and CHST2, two genes not previously described in osteosarcoma, were finally seen to be differentially expressed in all examined osteosarcoma cell lines and in samples between the different prognosis sample groups. Survival analysis also confirmed these two molecules could be used to predict the outcome of OSA patients.This work represents a rationale approach to the evaluation of microarray data and will be useful to identify genes that may be causally associated with metastasis. EREG and CHST2 will be likely considered as clinical molecular markers to predict the outcome of OSA.