Furthermore, we also evaluated the expression of proliferation marker, Ki-67, in the tumor tissues by IHC analysis, which showed that H1299-EV treatment led to an upregulation of Ki-67 positive expression but treatment with BEAS-2B-EVs + Smad9 diminished Ki-67 positive expression when compared with BEAS-2B-EV treatment (Fig. 7j). This evidence concerns the gene MKI67 and neoplasm.