BIRC5 and cancer: However, by comparing the binding intensity obtained for YY1 binding to the BIRC5 promoter in normal liver tissues vs. hepatocellular carcinoma, it is possible to observe that YY1 shows a stronger interaction with the BIRC5 promoter in cancer tissues than in normal ones (i.e., strength of 418 in normal cells vs. 1000 in cancer cells; Figure 1B and Table S2).