GSTM1 and hemophagocytic syndrome: Laboratory work-up revealed Hb 7.6 g/dl, low reticulocyte count (10,000/uL), a mild pericardial effusion, negative IgM/IgG viral panel for the main viruses that can be responsible for erythroblastopenia in childhood (such as Parvovirus B19, Epstein-Barr virus, cytomegalovirus, human herpes virus type 6, and echovirus) and complete absence of erythroblasts and signs of erythrophagocytosis at the bone marrow needle aspiration [Figs. 1 and 2], resembling morphological signs such as in hemophagocytic lymphohistiocytosis (HLH).