A system for a vehicle includes a hollow axle, a wheel hub which surrounds the axle, bearings provided therebetween, at least one nut having a predetermined inner diameter mounted on an end of the axle, and a hub cap mounted to the wheel hub. A slot is formed through the slot region of the coated substrate. In another aspect, the method can include identifying a treatment area that comprises one or more lesions containing metastatic cells; and administering a TLR7 agonist to the treatment area in an amount effective for treating the lesion. The first arm is sized to fit through the first slot of the first wing such that the first twistable section and the base member are on opposite sides of the first wing; and the second arm is sized to fit through the second slot of the second wing such that the second twistable section and the base member being on opposite sides of the second wing.