Nuclear Translocation of Procaspase-3 by TRB3 Figure 3. TRB3 inhibits CASP3 activation and subsequent apoptosis under ER stress condition. (A) HeLa cells were treated with the indicated concentrations of tunicamycin for 8 hr. The effective concentration of tunicamycin needed for inducing TRB3 expression was determined PLoS ONE | www.plosone.org 5 August 2012 | Volume 7 | Issue 8 | e42721