Following the observation that potent anti-lymphoma activity was elicited by an agonistic antibody to the T cell co-stimulatory molecule 4-1BB (CD137) [146], anti-4-1BB was combined with an empty SV vector to treat an A20 B cell lymphoma BALB/c tumor model [147]. Here, TNFRSF9 is linked to B-cell non-Hodgkin lymphoma.