Figure 8 shows the keyword timeline. Timeline chart showing keywords in clusters by their appearance date. Keyword color matches cluster label color. A total of ten clusters are generated: “selective-inhibition,” “expression,” “tert promoter mutations,” “principles,” “addiction,” “colorectal cancer,” “activation,” “epigenetic regulation,” “prostate-cancer,” “brd4”. Moreover, Figure 9 also showed the top 25 keywords with the strongest citation bursts. Here, BRD4 is linked to prostate cancer.