Treatment with the sp94dr/miR-26b mimic nanoparticles plus doxorubicin had an inhibitory effect on tumorigenesis in vivo, similar to the in vitro studies (Figure 5A, C and D). There was no significant change in the body weight of the mice after treatment in the different groups (Figure 5B). Ki-67 staining and a TUNEL assay found that treatment with the sp94dr/miR-26b mimic nanoparticles plus doxorubicin significantly decreased the tumor cell proliferation rates and increase tumor cell apoptosis compared to the other groups (Figure 5E-F). This evidence concerns the gene MKI67 and neoplasm.