In this study we demonstrated that the SHP2-D61Y mutation exclusively expressed in T cells did not result in the onset of a proliferative disorder, whereas Ptpn11D61Y expression in mice with the Cre recombinase driven by the cd4 promoter led to splenomegaly probably caused by an increase of total cell numbers in the spleen (Figure 1). Here, PTPN11 is linked to Splenomegaly.