HIPK2 and gastric cancer: Noticeably, our study is the first report the role of HDAC5 in the regulation of p16INK4a expression in GC cells, thus providing a novel HDAC5-mediated pathway in cancer, in addition to the TAp63/maspin, HIPK2/HIF1α, and p65/NF-κB pathways [29,43,44].