SIRP-α also known as SHPS1, SIRPA is a member of the signal-regulatory-protein (SIRP) family. SIRP-α plays a crucial role in modulating immune responses by negatively regulating the PI 3-kinase pathway, which is essential for controlling cell motility and survival in response to growth factors and oncogenic signals. SIRP-α is primarily located in the cell membrane, where its extracellular domain features three immunoglobulin-like structures that facilitate interactions with other proteins, while its cytoplasmic region contains four potential tyrosine phosphorylation sites that are critical for downstream signaling. Notably, SIRP-α interacts with the Src homology 2 domain-containing protein-tyrosine phosphatase SHP-2, and when phosphorylated, serves as a substrate for activated receptor tyrosine kinases, thereby influencing various cellular processes.