E2F1 and hepatocellular carcinoma: In addition, when we co-transfected the HCC cells with plasmids expressing YAP and those expressing uc.134, the decrease in the mRNA level of CYR61, c-Myc, diap1, and E2F1 was reversed by YAP, indicating that YAP is responsible for the uc.134-mediated gene regulation.