using a new differentiation antigen , okt17 , which recognizes a surface antigen present on the majority of resting normal peripheral t lymphocytes but is present only on a subset of okt4+ cells after activation , evidence was obtained that two functionally mature subsets can be distinguished within the okt4+ population itself : okt4+17+ radiosensitive suppressor cells and okt4+17- radiosensitive helper cells .
C0003324
differentiation antigen
C0003339
surface antigen