MMP9 and lung adenocarcinoma: Several TGF-β-responsive genes, including WWP1, CARM1, RASGRP1, THBS1, KCTD5, SGCA, EIF3S6, MCAM, FXR2, MTMR3, SOCS3, SLC2A4RG, MMP2, MMP9, and HSP47, have been previously identified in other cancer cell types such as A549 (lung adenocarcinoma) and HPL1D (lung epithelial cells) [26].