International Journal of Cancer Research1811-97271811-9735Academic Journals Inc.10.3923/ijcr.2007.1.12EndoChiaki SunZhifu MolinaJulian R. AttewellJohn R. YangPing 1200731To compare gene expression levels of lung cancer by real time quantitative reverse transcription polymerase chain reaction (qRT-PCR), choosing appropriate control genes for normalization of RNA input is important. We examined whether frequently used control genes are really appropriate. Eighteen lung cancer tissue samples were used in this study. Gene expression levels were measured by qRT-PCR and compared to the data generated by a DNA microarray experiment. The expression levels of four housekeeping genes that are most frequently used as control genes for qRT-PCR published reports in lung cancer were examined. Four test genes (TP53, laminin γ2, TGFα and cathepsin L2) were also examined. These genes had significantly higher expression in the high aggressive disease group. 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