CD4 and neoplasm: Expression of the CD3 antigen indicates that the tumor also comprises T lymphocytes as NKCs do not express this antigen (activated adult NKCs are negative for CD20, CD5, and surface CD3).[4] The tumor cells will lack other T-cell antigens such as surface CD3, CD4, CD5, CD57, CD16, and CD20.[7] Rarely, the tumor cells are positive for CD7, CD30, and CD45RO which is a T-cell marker.[8] In our case, the expression of CD7 was positive.