CD58 and plasma cell myeloma: Nevertheless, even in the absence of Fas, we do not observe an increase in TAC T cell viability or proliferation in the presence of LCL161, which suggests that LCL161-mediated costimulation is inconsequential in the presence of the full complement of adhesion molecules and costimulatory ligands (such as LFA-3 [40)] found on the myeloma cells.