Supporting a role of oxidative stress in p53 reactivation, normoxic wt p53 breast cancer cells [8] and multiple myelomas [9] increase their susceptibility to Prima-1 with agents that impair the GSH/ROS balance like the glutathione antagonist, buthionine sulfoximine, which antagonizes cellular anti-oxidant defence [8, 9]. Here, TP53 is linked to plasma cell myeloma.