TIA1 and neoplasm: Immunohistochemically neoplastic cells are typically CD3+ (Figure 1D), CD7+ (Figure 1E), CD103+, TCRβ+/− cells, CD4−, CD8−, and CD5−, mostly expressing CD30 with CD56 negativity [8], and demonstrate an activated cytotoxic phenotype (perforin+, granzyme B+, and TIA-1+) (Figure 1F), reflecting the origin of the tumor from cytotoxic IELs [8].