Identification of twenty-two candidate markers for human osteogenic sarcoma. Since osteogenic sarcoma (OGS) predominantly affects children, its etiology and progression may be determined more by genetic than environmental factors. A few genes have been associated with OGS, however, their value in the diagnosis and/or prognosis of the disease remains poor. Evidently, more markers need to be identified for improving management of patients with OGS. To identify potential genetic markers for OGS, we have extended preferential amplification of coding sequences (PACS) to screen multiple samples simultaneously. The extended method is termed multi-PACS. Multi-PACS was applied between a normal osteoblast and four OGS-derived cell lines to identify differentially expressed coding sequence tags (dCST) that identified 145 dCSTs. Subsequently, differential mRNA expression was validated for a chosen subset of 22 dCSTs. These chosen dCSTs include among others cyclins D and E, two cyclin dependent kinases, two other kinases, transcription factors E2F4, E2F5, and p130, a DNA repair gene, a gene for the signalosome subunit, and potential guanine nucleotide binding factors. We infer that these genes could be so easily identified because PACS preferentially identifies coding instead of non-coding sequences. We also infer that these genes identify signaling pathways pertinent to OGS. mRNA expression profile of these 22 genes/dCSTs generated distinct expression signature of the OGS-derived cell lines suggesting that further work on clinical samples with these dCSTs will yield valuable information for OGS. We conclude that these 22 genes/dCSTs are candidate markers for OGS.