In a cohort of 98 NSCLC patients with ALK gene rearrangements, we investigated the role of Tumor Protein (TP53) gene mutations in predicting patients prognosis...we observed that TP53 non-disruptive mutations were able to predict worse OS in the overall case series. Moreover, a worse PFS was seen in the subgroup of patients with TP53 non-disruptive mutation, in first-, second-, and third line of treatment. Our results show that mutations affecting TP53 gene, especially non-disruptive mutations, are able to affect prognosis of ALK-rearranged NSCLC patients....In the present study, 21 patients received an ALK-TKI agent as a first-line treatment, 57 as a second-line, and 28 patients as a third-line treatment.