Furthermore, altered expression of several genes of the pathway, including DDX4, HENMT1, MAEL, PDL6, PRMT5, TDRD1, TDRD6, TDRD9, TDRKH and WDR77, suggesting that the piRNA pathway is functional in liver and its activity is modified in the liver cancer (Supplementary Figure S1). This evidence concerns the gene TDRD6 and liver cancer.