PTK2 and lung cancer: Smoking is an important environmental factor in lung cancer, and a recent study confirmed that smoking activates the c-Src/FAK pathway (Stading et al., 2021), subsequently promoting lung carcinogenesis and progression (Zhou et al., 2019), drug resistance (Kang et al., 2013), and maintenance of KRAS-driven lung adenocarcinoma (Zhou et al., 2018).