We further investigated whether YAP and TAZ control mTORC1 activity in HB cells. For this goal, we silenced YAP, either alone or in association with TAZ, using siRNAs in Hep293TT and HepG2 cells. We found that, indeed, when YAP and TAZ were concomitantly silenced, p-RPS6 levels were significantly decreased (Figure 5A). Next, we determined whether YAP and TAZ modulate SLC38A1 expression. Again, YAP alone, TAZ alone or YAP and TAZ together were silenced in Hep293TT and HepG2 cells. Expression of SLC38A1 and YAP/TAZ target genes (CTGF and cysteine-rich 61 or CYR61) was analyzed using qRT-PCR. As expected, concomitant silencing of YAP and TAZ triggered downregulation of CTGF, CYR61, and SLC38A1 in Hep293TT and HepG2 cells (Figure 5B). Finally, using chromatin immunoprecipitation (ChIP) assay, we found that YAP binds to the promoter region of SLC38A1 (Figure 5C) in HepG2 and Hep293TT cells, supporting the hypothesis that YAP directly regulates SLC38A1 expression in HB cells.