NAMPT and Ewing sarcoma: Although studies in preclinical in vivo models and clinical trials of PARPis have disappointingly failed to demonstrate worthwhile response in Ewing sarcoma patients 70, the synergistic efficacy combining PARPis with nicotinamide phosphoribosyl transferase inhibitors (NAMPTis) has shown in vitro and in vivo models in Ewing sarcoma, hopefully showing its potential for use in Ewing sarcoma patients 71.