EGFR and Pleural effusion: At the time of disease progression in the first-line setting, EGFR molecular testing was performed with the cobas®EGFR Mutation test v2 using plasma-based liquid biopsy in 94 (97.9%) patients, and a tissue/cytology sample in the remaining two patients (2.1%; one sample was tissue from the site of the primary tumor and one was pleural effusion).