In vivo and in vitro studies with the model showed that exogenous rhTβ4 alleviated the impairment of lung function and severity of damage of the alveolar structure by the pulmonary fibrosis and inhibited the proliferation of LC tumor growth, which possibly associated with Tβ4 inhibitory effect on the JAK2/STAT3 signaling pathway. Here, STAT3 is linked to pulmonary fibrosis.