document: Flow Cytometry analysis. U87MG cells (6×104 per well) in 6-well plates were treated with 1 μM VLP-based samples (TrQβ VLPs, rQβ@b-3WJsiEGFR Let-7g, and TrQβ@b-3WJsiEGFR Let-7g) for 72 h were washed three times with 2% FBS contained PBS (pH=7.4). After that, all samples were fixed by 4% paraformaldehyde for 15 min and permeabilized by 0.1% triton X-100 solution for 15 min, the cells were separated into three groups (105 cells/mL for each). Then, those cells were blocked by 1% BSA solution for 20