In this in vivo experiment, we found that the combination of Rhein and RAD001 significantly reduced tumor weight and volume, repressed PI3K/AKT/mTOR pathway activation, and decreased tumor cell proliferation marker Ki-67 expression than the administration of Rhein or RAD001 alone, which indicated RAD001 and Rhein combination exerted synergistic cancer prevention on GC in vivo xenograft model. This evidence concerns the gene MKI67 and cancer.