RB1 and hepatocellular carcinoma: To further evaluate the role of AHR-HDAC8 signaling in the proliferation and tumorigenesis of HCC, hepatoma cells treated with HDAC8-specific inhibitors, PCI-34051, and 1-Naphthohydroxamic acid (1-NTHX) [26, 27], showed enhanced expression of RB1 and p53, as well as a lower level of proliferative activity (Figure 5C and 5D).