After removal of the Transwell insert from the plate, 70% ethanol was included for 10 min for mobile fixation and crystal violet was included to stain the invading colony. Briefly, cells ended up plated on top of the filter membrane in a Transwell insert and incubated at 37°C and 5% CO2 for ten min to let them to settle. After centrifugation, the cells were being resuspended and incubated with PI/RNase staining buffer for fifteen min.