We present the case of a patient diagnosed with stage IV lung adenocarcinoma….The patient was found to have an EGFR exon 19 (L747P) mutation, as evident in her liquid biopsy...this patient showed a substantial response when treated with erlotinib combined with epigenetic therapies, consisting of DNA methyltransferase and histone deacetylase inhibitors. For more than 8 years, the patient has been responding to combination therapy with a normal quality of life.