ANOS1 encodes anosmin-1, an extracellular glycoprotein that functions as a cell adhesion molecule with dual roles in neuronal development and reproductive axis formation 1. The protein exhibits chemoattractant activity for olfactory epithelial cells and promotes axon guidance, particularly in patterning olfactory neuron projections to the cortex. During fetal development, GnRH and olfactory neurons migrate together from the olfactory placode, with anosmin-1 facilitating this coordinated migration 2. ANOS1 mutations cause X-linked recessive Kallmann syndrome, characterized by hypogonadotropic hypogonadism combined with anosmia or hyposmia 13. This results from impaired GnRH neuron migration to the hypothalamus, leading to gonadotropin deficiency and absent puberty. ANOS1 variants account for a substantial fraction of congenital hypogonadotropic hypogonadism cases 4. Clinically, patients present with delayed puberty, infertility, and olfactory dysfunction; treatment with testosterone or GnRH/gonadotropin therapy can restore sexual development and fertility 2. Beyond reproductive development, elevated ANOS1 expression has been associated with gastric cancer progression, correlating with increased proliferation, invasion, and worse prognosis 5, suggesting broader biological significance in cell adhesion and migration processes.