PTPRC and Splenomegaly: Being a secondary lymphoid organ, the spleen is the site for maturation and storage of lymphocytes and splenomegaly is often associated with splenic hyperfunction and elevated immune cell turnover.S3 We performed flow cytometry analyses of splenic immune cells and found that CD45+ cells increased 3.4‐fold in PBS‐treated C26 mice and 2.8‐fold in RK‐treated C26 mice compared with the respective control mice (Figure3B).