NQO1 and neoplasm: NQO1 is also highly expressed in other tumor cells, such as breast cancer (Marin et al., 1997; Yang et al., 2014), lung cancer (Siegel et al., 1998; Bey et al., 2007; Li et al., 2015), prostate cancer (Dong et al., 2010), gastric cancer (Lin et al., 2014), colon cancer (Ji et al., 2014), pancreatic cancer (Ough et al., 2005), head and neck cancer (Li et al., 2016), and cholangiocarcinoma (Wakai et al., 2011).