In the recent years, the anti-cancer potential of PTC-209, a small specific inhibitor of Bmi-1, has been evaluated and showed efficacy, in vitro and in vivo, against various human cancers, such as colorectal (Kreso et al., 2014), ovarian (Dey et al., 2016), glioblastoma (Kong et al., 2018), head neck squamous cell carcinoma (Wang et al., 2017), multiple myeloma (MM) (Alzrigat et al., 2017), and chronic and acute myeloid leukemia (Nishida et al., 2015). Here, BMI1 is linked to head and neck squamous cell carcinoma.