EGFR and neoplasm: Liquid biopsy can be used to identify T790M mutations even if the tumor tissue is not available, thereby maximizing the number of patients who may benefit from subsequent treatment with osimertinib in the case of T790M-positivity [21]; indeed, analyses of blood samples from 119 patients who had progressed on first- or second-generation EGFR-TKI revealed a plasma T790M-positivity of 71%.