tokens: The differentiating agent retinoic acid ( RA ) has been previously reported to interfere with 12-O-tetradecanoyl-phorbol-13-acetate ( TPA ) /Ca ( 2+ ) -induced signals for the regulation of the -96 to -66-bp octamer motif found in the enhancer for the interleukin ( IL ) -2 gene , which encodes a major T lymphocyte growth factor .