Furthermore, most other parameters known to be associated with OS of stage IV EGFR+ NSCLC, such as the histological subtype, type of EGFR mutation, TP53 status, presence of co-mutations, especially in TP53, frequency of T790M development (5–7, 9), were equally distributed among de novo and secondary cases (Table 1). This evidence concerns the gene TP53 and non-small cell lung carcinoma.