B02 is a RAD51 inhibitor. RAD51 is a homologous recombination protein, involved in the repair of double strand breaks in DNA. It is often overexpressed in cancers, making it an interesting target for anti-cancer therapies. Suppressing RAD51 activity increases the sensitivity of cancer cells to other therapies. In human breast cancer cells, B02 increased the anti-cancer effect of doxorubicin, etoposide, topotecan, and cisplatin.