Cytomegalovirus (CMV) infection remains one of the most common and challenging post-transplant infections. Children with inborn errors of immunity (IEI) and T-cell dysfunction are at high risk for CMV infection, which can be complicated by refractory and/or resistant cases. This case describes a Nepalese girl with MHC class II deficiency, who presented at 3 months of age with CMV and Pneumocystis jirovecii pneumonia. Hematopoietic stem cell transplantation (HSCT) was planned as a …