HES1 and cancer: A handful of Notch direct target genes have been reported, including HES1 (Espinosa et al., 2010), HEY1 (Xie et al., 2020), p21 (Monahan et al., 2009), c-Myc (Weng et al., 2006), and Slug (Niessen et al., 2008), whose dysregulation is frequent in cancer.