SIRPB1 (signal regulatory protein beta 1) is an immunoglobulin-like cell surface receptor that functions primarily in immune signaling regulation and cellular activation. The protein negatively regulates receptor tyrosine kinase-coupled signaling processes while also participating in tyrosine kinase SYK recruitment 1. When associated with TYROBP, SIRPB1 triggers activation of myeloid cells, particularly macrophages 1. Mechanistically, SIRPB1 activation leads to SYK phosphorylation and subsequent activation of calcium, MAPK, and NF-κB signaling pathways, primarily in myeloid-derived cells 1. The protein regulates inflammatory factor expression including IL1RA, CCL2, and IL-8 in macrophages through SYK-dependent pathways 1. SIRPB1 demonstrates significant disease relevance across multiple conditions. In cancer, gene amplification occurs in up to 37.5% of prostate cancer specimens, where SIRPB1 promotes cell proliferation via Akt activation 2. The protein also influences glioma progression by reprogramming the tumor microenvironment through macrophage activation 1. Additionally, SIRPB1 shows associations with autoimmune conditions like myasthenia gravis, where it participates in CD4+ T-cell activation pathways 3. Copy number variations in SIRPB1 have been linked to impulsive-disinhibited personality traits and brain aging 45. These findings establish SIRPB1 as a potential therapeutic target across inflammatory, oncological, and neuropsychiatric conditions.