Generation of TC-PTP knockout mice showed its critical role in hematopoiesis and immune function in that TC-PTP knockout mice were severely defective in the hematopoietic compartment and all homozygous mice died between 3 and 5 weeks of age due to diarrhea, splenomegaly, lymphadenopathy, and anemia7. This evidence concerns the gene PTPN2 and Splenomegaly.