NFKB1 and cancer: Previously, we demonstrated that highly purified sulfur [4] and herbal medicines, such as Caesalpinia sappan [5], Coptidis rhizoma [6], and verticinone [7], exerted antitumor effects on oral cancer cells in vitro. Moreover, we showed that a single compound isolated from Caesalpinia sappan heartwood, isoliquiritigenin 2′-methyl ether (ILME), had antioral cancer effects involving mitogen-activated protein kinases (MAPKs) and the nuclear factor-κB (NF-κB) pathway [8].