TP53 and cancer: PTTG1 (Securin) Promotes genetic instability and EMT. Overexpressed PTTG1 drives EMT and cell motility in cancer cells. May enhance secretion of angiogenic factors (through p53 inhibition). In fibroblasts, PTTG1 can promote proliferation and matrix production. In MSCs, PTTG1 supports proliferation, possibly aiding their tumorigenic roles.