EGFR and non-small cell lung carcinoma: The finding that compound EGFR mutations (where an EGFR-TKI sensitizing or other mutation is identified together with a mutation of unknown clinical significance) (39) are particularly sensitive to treatment with afatinib is notable, as these mutations are identified in up to one quarter of EGFR mutation-positive NSCLC tumors and are associated with poor prognosis (39–41).