CASP9 and cancer: Several intron and promoter region polymorphisms in CASP9 have been associated with incidence and progression of various cancers, including lung (Yoo et al., 2009; Lee et al., 2010; Lin et al., 2012; Xu et al., 2012), esophagus (Liu et al., 2010; Costa et al., 2019), liver (Zhang et al., 2017), breast (Theodoropoulos et al., 2012), and hemopoietic malignancies (Lan et al., 2007; Hosgood et al., 2008; Lan et al., 2009; Kelly et al., 2010; Cingeetham et al., 2014).