TP53 and AIDS dementia complex: TP53 is commonly mutated in 51% of ADC and 82% of SCC samples, respectively, while KRAS is predominantly mutant in adenocarcinoma (ADC) but amplified or overexpressed in squamous cell carcinoma (SCC) (Mogi and Kuwano, 2011; Westcott and To, 2013; Wang et al., 2014).