TP53 and squamous cell carcinoma: Consistently, the activated NOTCH1 level positively correlated with poorer survival of NSCLC patients (n = 420, consisting of 176 squamous cell carcinomas and 244 adenocarcinomas) without p53 mutations (48.9% of the entire cohort of 420 patients), suggesting that targeting NOTCH1 may be a useful strategy for treatment of certain lung cancer patients, especially those with gain-of-function NOTCH1 mutations and/or without p53 mutations [40].