CD52 and adult T-cell leukemia/lymphoma: PTCL subtypes such as PTCL/NOS, AITL, ATLL, HSTL, and T-PLL were shown to have high frequency of CD52 expression (> 90%) by flow cytometry and IHC analysis, while CD52 expression was low in ALCL and ENT/NKCL [18, 19].