PTK2 and lung adenocarcinoma: As LKB1 has recently been shown to interact with and inhibit FAK [43], and ~30% of lung adenocarcinomas harbour an inactive LKB1/STK11 gene [41], we investigated whether A549 cells may be more sensitive to FAK inhibitors owing to an increased reliance on FAK signalling due to their lack of a LKB1-FAK inhibitory interaction.