['Epidermal growth factor receptor (EGFR) stimulation markedly increases cyclin D1 protein expression. Recently, it has been reported that cyclin D1 expression was increased in EGFR mutant cell lines; however, the expression status of CCND1 in EGFR mutant lung cancer tissues has not been reported.', 'We have investigated the CCND1 messenger RNA (mRNA) levels and other clinicopathologic data in 74 lung cancers. The CCND1 mRNA levels were quantified by real-time reverse-transcriptase polymerase chain reaction using LightCycler.', 'The CCND1/GAPDH mRNA levels were significantly higher in adenocarcinoma (35.125 +/- 37.387) than in non-adenocarcinoma (15.2 +/- 24.699; P = .0158), and CCND1/GAPDH mRNA levels were not significantly different among smoking status, sex, or pathologic stage. The CCND1/GAPDH mRNA levels were significantly higher in lung cancer with EGFR mutation (39.713 +/- 41.265) than in lung cancer without EGFR mutation (21.805 +/- 29.152; P = .0338). CCND/GAPDH mRNA expression did not correlate with prognosis of lung cancer.'] Is cCND1 messenger RNA expression correlated with EGFR mutation status in lung cancer?