Data from clinical trials have shown osimertinib to have a 66% response rate against NSCLC tumours that have become resistant to TKI treatment due to the T790M mutation [9], and has been approved by the US Food and Drug Administration and the European Commission for use in T790M-positive NSCLC patients who have progressed on EGFR TKI therapy. Here, EGFR is linked to non-small cell lung carcinoma.