SPSS17.0 software was used to analyze the data. 
SPSS17.0
Methods: The expressions of CDK6 mRNA in fresh LSCC specimens, the adjacent normal mucosa of LSCC, and cell lines of LSCC were detected with quantitative real time polymerase chain reaction, pcDNA3.1(+) CDK6 plasmids were respectively transfected into the LSCC cells, and MTT assay and clone formation assay were performed to evaluate the growth of LSCC cells. 
pcDNA3.1(+)