AIM To investigate SBA2 expression in CRC cell lines snd surgical specimens of CRC and sutologous healthy mucosa.METHODS Reverse transcription-polymerase chain reaction (RT-PCR) was used for relative quantification of SBA2 mRNA levels in 4 human CRC cell lines with different grades of differentiation and 30 clinical samples.Normalization of the results was achieved by simultaneous amplification of β-actin as an internal control.RESULTS In the exponential range of amplification, fairly good linearity demonstrated identical amplification efficiency for SBA2 and β-actin (82%). Markedly lower levels of SBA2 mRNA were detectable in tumors, as compared with the coupled normal counterparts ( P ＜ 0.01 ). SBA2 expression was significantly (0.01 ＜ P ＜0.05) correlated with the grade of differentiation in CRC,with relatively higher levels in well-differentiated samples and lower in poorly-differentiated cases. Of the 9 cases with lymph nodes affected, 78% (7/9) had reduced SBA2 mRNA expression in contrast to 24% (5/21) in nonmetastasis samples (0.01 ＜ P ＜ 0.05 ).CONCLUSION SBA2 gene might be a promising novel biomarker of cell differentiation in colorectal cancer and its biological features need further studies.