ALK and non-small cell lung carcinoma: The study of these patients showed that: (i) ALK-rearrangement was strongly associated with younger age at diagnosis (i.e., the frequency of ALK-rearrangements in NSCLC occurring before 40 years was very high (25−50%), while it was markedly lower in patients after 50 years (2−8%)); (ii) EGFR mutations were clearly associated with lower tobacco exposure and moderate to high differentiation [325] (Figure 5).