Based on the findings that the level of Rad51 mRNA is positively correlated to the status of estrogen receptors, and that ERβ inhibits homology-directed DNA repair by facilitating nuclear interaction between Rad51 and insulin receptor substrate 1 (IRS-1) in ERα-low-expressing medulloblastoma, we hypothesize that Erb-041 may potentiate UVC-induced DNA DSBs through HR inhibition [16,17,18]. The gene discussed is IRS1; the disease is medulloblastoma.