Fig. 5
![Fig. 5](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs12864-017-3813-4/MediaObjects/12864_2017_3813_Fig5_HTML.gif)
Correlated expression between CHRNA4 and CYP2A6. a The enriched Canonical Pathways of genes positively/negatively correlated with CHRNA4 in 119 normal liver samples. b Expression Pearson correlation coefficient between CHRNA4 and nicotine-metabolism related genes. c CHRNA4 and nicotine-metabolism related genes were significantly down-regulated in hepatocellular carcinoma compared to normal liver samples. ANOVA was performed to detect statistical significance. d Module of correlation and regulation between CHRNA4 and CYP2A6 in human hepatocytes. CHRNA4 and CYP2A6 are co-regulated by HNF4A and RXRA. The CHRNA4 nicotinic receptor on the cell membrane may trigger downstream signaling pathways to stimulate regulation of CYP2A6 and itself