To evaluate the transmigrating activity of peripheral blood CD4+ T cells of HAM/TSP patients through the basement membrane, we previously investigated the transmigration of peripheral blood CD4+ T cells of HAM/TSP patients through the reconstituted basement membrane (RBM) using Transwell inserts, which were polyvinylpyrrolidone-free polycarbonate filters pre-coated with laminin on the lower surface and RBM (Matrigel) on the upper surface, respectively [65]. This evidence concerns the gene CD4 and tropical spastic paraparesis.