TIGIT and plasma cell myeloma: Based on the remarkable efficacy of anti-TIGIT mAbs in solid tumors and potential immune-killing effects mentioned above in preclinical research, human anti-TIGIT mAbs are being tested in phase 1/2 clinical trials either as a monotherapy or, in most studies, in combination with anti-PD-1/PD-L1 antibodies or chemotherapies for the treatment of malignant lymphoma and multiple myeloma (Table 1).