ZAN (zonadhesin) is a sperm membrane protein located on human chromosome 7 that plays a critical role in gamete recognition and fertilization. The gene maps to chromosome 7 in humans, positioned near the ZP3 gene encoding an egg extracellular matrix protein 1. ZAN functions as a species-specific binding protein that recognizes and adheres to the zona pellucida, the extracellular matrix surrounding the oocyte 1. This interaction is essential for sperm-egg cell-cell adhesion and represents a key molecular event in gamete recognition during fertilization. The protein exhibits structural characteristics consistent with extracellular matrix components and mediates the initial contact between sperm and egg through specific binding interactions 1. While ZAN's primary physiological role centers on reproductive biology and early fertilization events, the provided literature does not contain information regarding disease relevance, clinical significance, or therapeutic applications of ZAN mutations or dysfunction. Further investigation would be required to establish whether ZAN variants contribute to infertility or other clinical pathologies.