Nager syndrome (NS) is an extremely rare disease that causes developmental problems and anomalies in facial bone structures and limbs. While the causative gene is known, its underlying mechanisms remain obscure. Researchers from Japan employed genetically engineered zebrafish and found that the mutation in the gene that causes NS, suppresses the Fgf8 levels. This, in turn, affects the expression pattern of a critical cell population called neural crest cells in facial development.