FOXO1 and hepatocellular carcinoma: We also determined FOXO1 expression in normal LO2 liver cells and HCC cells, real-time quantitative PCR assay found the mRNA level of FOXO1 in LO2 was the same as HCC cells (Additional file 3: Figure S3), but FOXO1 was downregulated in protein level in HCC cells (Additional file 4: Figure S4C), suggesting miR-135a inhibited the translation of FOXO1.