We report a 65-year-old patient with heavily pretreated, FRα-positive ovarian cancer who developed therapy-related myelodysplastic syndrome with increased blasts (MDS-IB2, DNMT3A-mutated) during therapy with MIRV in combination with carboplatin having received prior PARPi maintenance therapy. The gene discussed is FOLR1; the disease is myelodysplastic syndrome.