we conclude ( a ) il-1 alone is not a potent mitogen for balb/c3t3 cells , and does not bring cells out of the growth arrest go phase , ( b ) treatment with pdgf renders the cells more responsive to il-1 , ( c ) part of the il-1 action on competent cells may be characterized as progression inducing activity , further , ( d ) our results indicate that action of il-1 on pdgf-treated cells produces sustained dna synthesis for an extended period , perhaps by preventing the entry of cells into growth arrest go phase .
C0007595
cells
C0007634
the