ICOSLG and melanoma: Surface expression of ICOSL, 4-1BBL, and OX40L in B16 melanoma and TC-1 tumor cells was assessed by flow cytometry at 6, 12, 24, and 48 h after transfection with ssRNA-ICOSL, ssRNA-4-1BBL, or ssRNA-OX40L (hereafter referred to as ssRNA-ICOSL, ssRNA-4-1BBL, and ssRNA-OX40L, respectively).