CTLA4 and neoplasm: From this data, it is obvious to assume that altering CTLA4 expression, i.e., to enhance or downregulate its expression, will be an appropriate treatment regime in autoimmune diseases to enhance Treg-dependent tolerance induction, e.g., to prevent cardiac allograft rejection [143], or to inhibit this immune-suppressive reaction to enhance anti-tumor immunity, e.g., by using CTLA4-neutralizing antibodies [144].