The City of Hope-developed investigational small molecule selectively disrupts DNA replication and repair in cancer cells, leaving healthy cells unaffected, a new study reports. CONTACT Zen Logsdon 626-409-9367zlogsdon@coh.org The City of Hope-developed small molecule AOH1996 targets a cancerous variant of the protein  PCNA. In its mutated form, PCNA is critical in DNA replication and repair of all expanding tumors. Here we see untreated cancer cells (left) and cancer cells treated with AOH1996 (right) undergoing programmed cell death (violet). (Photo credit: City of Hope)LOS ANGELES — Researchers at City of Hope, one of the largest cancer research and treatment organizations in the United States, today published a new study explaining how they took a protein once thought to be too challenging for targeted therapy, proliferating cell nuclear antigen (PCNA), and developed a targeted chemotherapy that appears to annihilate all solid tumors in preclinical research. As the scientists conti