TP53 and breast cancer: In turn, Ramachandran et al. showed that azurin induces apoptosis in T-47D and ZR-75-1 breast cancer cells and mediates growth arrest of these cells through cell cycle arrest in the sub-G1 phase, ROS generation, up-regulation of p53, and up- and down-regulation of pro- and anti-apoptotic proteins, as well as DNA fragmentation; it was also observed that the concentration of azurin required to inhibit cell growth varied depending on the cell line tested.