pure recombinant interleukin 2 ( r-il2 ) was added to colony cultures that also contained the lectin phytohemagglutinin ( pha ) or the phorbol ester 12-0-tetradecanoylphorbol-13-acetate ( tpa ) to activate the cll cells .
C0031586
phorbol
C0039654
tetradecanoylphorbol