HDAC9 and cholangiocarcinoma: Based on the findings that ethanolic extracts of Thai noni juice (TNJ) products and Tiliacora triandra leaf powder possessing HDAC inhibitory activity enhance the anticancer effect against human cholangiocarcinoma (CCA) cells and reduce toxicity of 5-FU, cisplatin and gemcitabine in nude mouse xenograft models [22,23], we therefore hypothesize that KK4-PSE would enhance anticancer activity of cisplatin or 5-FU against cervical cancer cells both in vitro and in nude mouse xenograft models.