PDCD1 and angioimmunoblastic T-cell lymphoma: For AITL that most often express the two characteristic indicators of PD-1 and CD10, it is usually CD4-positive clonal T cells, and CD5 is not easily lost; CD30, CD38, and HLA-DR are positively correlated with the expression of indicators reflecting clonal T cell activation and Ki-67, which reflects proliferation ability; CD8-positive clonal T cells are prone to express CD56 and CD57, and the expression of CD2 is stable.