TTF1 and neoplasm: His tumor was positive for AE1/AE3, EMA, CD56, CD34, ALK, DOG1 (focal), and synaptophysin and was negative for chromogranin A, WT1 (N-terminus), WT1 (C-terminus), myogenin, desmin, NUT, ETV4, CD31, h-caldesmon, smooth muscle actin, claudin-4, MUC4, S100, SOX10, calretinin, BCOR, SALL4, Pan-TRK, NKX2-2, and TTF-1 [4].