The Serpin B3 protein exhibits versatility in cellular regulation and may act as a papain-like cysteine protease inhibitor to modulate immune responses against tumor cells. Its dual role extends to inhibiting UV-induced apoptosis by inhibiting c-Jun NH (2) -terminal kinase (JNK1) activity, suggesting that Serpin B3 is involved in the stress response. Serpin B3 Protein, Human (HEK293, His) is the recombinant human-derived Serpin B3 protein, expressed by HEK293 , with C-6*His labeled tag.