because only the proliferating st were found to react with a monoclonal antibody , which is thought to be directed at the il 2 receptor ( anti-tac ) , our data suggest that pha is required for the induction of expression of receptors for il 2 in those st subpopulations that are able to proliferate in the presence of il 2 generated in situ .
C0086418
st
C0021756
il 2