Western blotting demonstrated that the expression of matrix metallopeptidases 2, 7, and 9 (MMP2, MMP7, and MMP9), three important regulators of cancer invasion and metastasis, was markedly increased in GR and OR cells (Figure 1F and Supplementary Figure 2F), suggesting that acquired gefitinib/osimertinib resistance enhances the in vitro metastasis potential of NSCLC cells associated with upregulation of MMP family members. The gene discussed is MMP9; the disease is cancer.