SIVA1 is a proapoptotic protein encoded on chromosome 14 that functions as a critical regulator of programmed cell death through multiple molecular mechanisms 1. Primary function: SIVA1 promotes apoptosis by interacting with CD27 death receptors and inhibiting anti-apoptotic BCL2 family proteins, particularly BCL-XL 1. Mechanism: SIVA1 achieves this through physical interactions with key signaling proteins. It binds XIAP and TAK1, suppressing NFκB activation while enhancing JNK signaling to favor apoptosis 2. SIVA1 also interacts with p53 and stathmin, with the latter interaction stabilizing microtubules and inhibiting epithelial-mesenchymal transition 3. Additionally, SIVA1 directs RAD18 E3 ubiquitin ligase to PCNA for DNA damage tolerance 4. Disease relevance: SIVA1 demonstrates dual roles in cancer biology 1. Low SIVA1 levels correlate with enhanced metastasis in breast cancer, and SIVA1 knockdown promotes tumor dissemination while overexpression inhibits it 3. Conversely, FTO-mediated m6A demethylation reduces SIVA1 levels, promoting 5-fluorouracil resistance in colorectal cancer 5. Clinical significance: Recombinant SIVA1 protein exhibits anticancer activity in nasopharyngeal carcinoma, inhibiting proliferation and invasion while promoting apoptosis 6. ES-induced SIVA1 upregulation enhances wound healing through p53 pathway modulation 7, suggesting therapeutic potential in both oncology and tissue repair.