Patients with thrombocytopenia showed distinct clinical and biological features with a lower frequency of typical mononucleosis symptoms such as sore throat and lymphadenopathy, a lower frequency of positive heterophil antibodies, a higher serum bilirubin concentration and prothrombin time, lower blood leukocyte and lymphocyte counts, lower concentrations of serum immunoglobulin G and immunoglobulin A and a larger spleen size [48]. Here, F2 is linked to Thrombocytopenia.