“…Among them, polyethylenimine (PEI) is considered as the most effective. Preclinical data are available for hepatocellular carcinoma, 1 pancreatic tumors, 2,3 ovarian carcinoma, 4,5 head-andneck cancer 6,7 and lung cancer. [8][9][10] More importantly, the first clinical data were published recently, which show dramatic bladder tumor remission in two patients.…”