A newly described small molecule inhibitor called AOH-1996 targets a cancer-associated isoform of PCNA (caPCNA), leading to a very broad therapeutic window. Researchers at City of Hope, a cancer research and treatment organization in California, reported on AOH-1996 in the Aug. 1, 2023, online edition of Cell Chemical Biology. Genes involved in replication and repair pathways are essential for the growth and survival of cancer cells. Proliferating cell nuclear antigen (PCNA) is a key player in DNA replication via a homotrimer formation that acts as a molecular sliding clamp around the DNA double helix.