TRAK2 and in situ carcinoma: Our findings are also consistent with observations that autoantibodies in patient sera bind brain cells (10, 85); as indicated in Tables 1 and 2, our data show that at least 10% of patients with CIS express antibodies toward the neural cell-surface proteins GRIN1, GRIA1, and SORT1 and the neural intracellular antigens KIF1C, SYNJ2, EXPH5, KCTD17, CBX6, and TRAK2.