PRCA: pure red cell aplasia; Ig: immunoglobulin; het: heterozygous; hom: homozygous; GCSF: granulocyte-colony stimulating factor; IVIG: intravenous immunoglobulin; HSCT: hemopoietic stem cell transplantation, TNF: tumor necrosis factor. The gene discussed is TNF; the disease is pure red-cell aplasia.