Studies have demonstrated that ACT using naïve or effector Ptpn22-/- OT-I TCR transgenic CD8+ T cells is superior to control OT-I ACT in mediating clearance of ID8 ovarian carcinoma or EL4 lymphoma cells expressing weakly antigenic pOVA as tumor-associated antigens32,47,104 (Figure 2). This evidence concerns the gene PTPN22 and neoplasm.