The gene family of ubiquitous transcriptional factors Rel/NF-kappa B participates in several critical cellular events ultimately influencing the fate of a cell. In the cytoplasm of all eukaryotic cells, the Rel/NF-kappa B proteins occur bound to their inhibitors, the I kappa B proteins. When stimulated, they become phosphorylated and degraded by 26S proteasome releasing Rel/NF-kappa B. Active Rel/NF-kappa B heterodimers then enter the nucleus, bind to a -kappa B coupling element and start transcription of kappa B-regulated array of genes involved in immune, antiapoptotic and inflammatory events. Part of the pharmacological effects of glucocorticoids, acetylosalicylic acid an ibuprofen may stand on influencing the Rel/NF-kappa B pathway. New compounds with cytotoxic and immunomodulatory properties acting specifically on the cascade of Rel/NF-kappa B signaling system are expected to be synthesized.