BIRC5 and cancer: Nuclear Survivin has been associated with a better prognosis, whereas cytoplasmic Survivin is associated with in some cancer types poor clinical outcome.21 In gastric cancer, the five-year survival rate of patients with positive Survivin expression is significantly lower than Survivin-negative patients.22 Survivin protein undergoes post-translational modifications, including acetylation, phosphorylation and ubiquitylation,23 and these processes modulate Survivin activity.