Since the above RTK results suggest that the JAK3 signalling pathway is activated and because the JAK/STAT signalling pathway is considered one of the central communication nodes in cellular functions, we examined whether the expression of Signal transducer and activator of transcription 2 (STAT2) was secondarily increased in EGFR-TKI-resistant lung adenocarcinoma. Here, EGFR is linked to lung adenocarcinoma.