MMP9 and neoplasm: In this context, MMP-9 derived from tumor cells, including NSCLC (Liu et al., 2010) and neutrophils, promotes proteolytic activation (Kobayashi et al., 2014) of latent TGF-β1 in the TME, resulting in immunosuppression and tumor progression (Juric et al., 2018; Germann et al., 2020).