Hematopenia of undetermined significance, whose standardized name is “idiopathic hemocytopenia of undetermined significance,” may be effectively treated with cyclosporine A (CsA), glucocorticoids, and immunoglobulin C. The term “idiopathic hemocytopenia of undetermined significance” is used to refer to a group of conditions whose cause is not known and which cannot be classified. 1. Idiopathic cytopenia of undetermined significance (ICUS) is a category of pancytopenia with an unclear etiology that cannot be classified at this time. 2. The diagnosis of ICUS requires adequate hematologic and non-hematologic investigations to exclude hematopoiesis caused by myelodysplastic syndromes (MDS), aplastic anemia (AA), paroxysmal sleep hemoglobinuria (PNH), autoimmune disorders, and neoplasms, as well as other hematologic and non-hematologic disorders. 3. At present, ICUS is mostly treated with cyclosporine, and hormone (methylprednisolone) shock or gammaglobulin can be added according to the condition. Most of the patients can be slowed down after receiving cyclosporine treatment, but there are still some patients with unsatisfactory treatment effect, and their condition has not been significantly improved. Since ICUS has a tendency to regress to MDS and leukemia, patients diagnosed with ICUS need to be closely followed up for a long time, and the myelocytology should be reviewed several times if necessary. It is recommended that ICUS patients under the guidance of a professional doctor for standardized treatment, the above drugs to avoid blind self-use.