EGFR and non-small cell lung carcinoma: Currently, the analysis of tyrosine kinase inhibitor-resistance in NSCLC to assess the presence of EGFR T790M mutation is by far the most common application of ctDNA analysis in routine diagnostics worldwide, with the FDA and the European Medicines Agency (EMA)’s most recent recommendations suggesting the use of liquid biopsy testing in those cases where no tissue material is available [158].