Analysis of surface expression on CLL cells did not reveal any significant correlation for GITR and GITRL (ρ = 0.168, p = 0.156) or 4-1BB and 4-1BBL (ρ = 0.170, p = 0.148) (Figure 1D,F) between each other. The gene discussed is TNFRSF18; the disease is B-cell chronic lymphocytic leukemia.