We found that GSK2578215A, a LRRK2 inhibitor, suppresses HR and increases sensitivity of ovarian cancer cells to Olaparib in vitro and in vivo; suggesting that combination treatment of an LRRK2 inhibitor and a PARP inhibitor may be a novel strategy to improve the effectiveness of LRRK2‐ expression ovarian cancers. The gene discussed is LRRK2; the disease is ovarian cancer.