There are several possible reasons: (1) different NSCLC lines were generated from various stages of lung cancer patients and the responsiveness of TGFβ signaling pathway were different during the cancer progression; (2) the combination of different key mutations in each cell line leads to various sensitivity to TGFβ1; (3) TGFβ1 responsiveness of NSCLC lines may be affected by their interaction with other players in the microenvironment. The gene discussed is TGFB1; the disease is lung cancer.