Interstitial deletion of human chromosome 9p21, resulting in loss of CDKN2A/B, is also widely regarded to be a critical event in the development of numerous diverse human cancers (for example, Kohno and Yokota 2006; Schiffman et al. 2010; Sarhadi et al. 2013; LaPak and Burd 2014; Su et al. 2014). The gene discussed is CDKN2A; the disease is cancer.