TNF and pulmonary fibrosis: Five studies evaluated the impact of Ginkgo biloba leaf extract on TNF-α levels in patients with pulmonary fibrosis, with two studies (Shi, 2016b; Xu and Liang, 2018) utilizing bronchoalveolar lavage fluid specimens (Figure 6C) and three (He et al., 2005; Xing et al., 2012; Guan, 2015) employing blood samples (Figure 6D).