In a Matrigel invasion assay, which detects the ability of cells invading a basement membrane matrix, LAM patient-derived TSC2-null cells in the control group passed through the transwell membrane more frequently and exhibited a greater invasive capability than LAM patient-derived TSC2-null cells transfected with IGFBP2 siRNA (p<0.001) (Figure 4F). This evidence concerns the gene IGFBP2 and lymphangioleiomyomatosis.