Immunostaining has revealed that AITL TIL-Ts often have a significantly larger proportion of CD4+ cells than CD8+ cells (defined as common AITL in our study), which is due to CD4 expression in neoplastic T-cells and a normal CD4+/CD8+ ratio in TIL-Ts (CD4+TIL-Ts outnumber CD8+TIL-Ts) (7, 8). The gene discussed is CD4; the disease is angioimmunoblastic T-cell lymphoma.