Han MS, Choi EH, Lee HJ, et al. - Given that cytomegalovirus (CMV) disease is underrecognized in retinoblastoma children, researchers explored rates of CMV infection and disease in this specific population receiving chemotherapy. One hundred seven patients were assessed for CMV infection determined by antigenemia assay or real-time PCR from a cohort of 164 individuals with retinoblastoma diagnosed from 2011 to 2018. In 2013, preemptive CMV screening was implemented. By tissue biopsy, culture, or ophthalmic examination, CMV disease was diagnosed. Individuals who began chemotherapy at < 12 months of age received preemptive therapies significantly more often compared with those started at ≥ 12 months. During chemotherapy in Korea, children with retinoblastoma can experience significant morbidity and even mortality from CMV infection. Preemptive screening and appropriate antiviral therapy can decrease CMV disease development (from 14% to 2.9%) and subsequent mortality.