POU5F1 and non-small cell lung carcinoma: Furthermore, in our study, silencing of Oct4 expression significantly reduced the expression and enzyme activity of Dnmt1 in CCE cells, while the overexpression of Oct4 obviously increased the amount of Dnmt1 in NCI-H157 cells (a line of human non-small cell lung cancer cells with a high endogenous Dnmt1mRNA level; Additional file 3: Figure S3).