FCGR1A encodes CD64, the sole high-affinity IgG Fc receptor in humans, functioning as a key mediator of both innate and adaptive immune responses 1. The receptor promotes antibody-dependent cellular cytotoxicity (ADCC) on monocytes and triggers phagocytosis, degranulation, and pro-inflammatory cytokine production 1. FCGR1A expression is regulated by functional genetic variants: rs1848781 in the promoter affects CD64 expression levels, while the non-synonymous variant rs1050204 (p.D324N) alters CD64-mediated immune functions 1. Beyond classical immunity, FCGR1A has emerged as a key inflammatory biomarker in multiple pathological contexts. In proliferative diabetic retinopathy, FCGR1A is predominantly expressed in microglia and represents a promising therapeutic target 2. Genome-wide association studies identify FCGR1A as a druggable target for insulin resistance with approved therapeutic options 3. In ischemic stroke, FCGR1A modulates microglial polarization via the AMPK-mTOR pathway; paradoxically, FCGR1A knockdown promotes anti-inflammatory M2 polarization and reduces stroke-induced injury 4. CD64+ monocytes show causal association with age-related macular degeneration risk through interactions with retinal pigment epithelium 5. FCGR1A expression also increases during viral infections and tuberculosis, correlating with disease severity and treatment outcomes 678.