FGF8 and holoprosencephaly: This comprehensive review explores the FGF8 expression in humans and mice, summarizes the involvement of FGF8 in various tissues including craniofacial, limbs, cardiovascular and urogenital system, nephrogenesis, lung, and brain development as well as developmental abnormalities resulting from the aberrant regulations of FGF8 such as skeletal abnormalities, ciliopathies, and holoprosencephaly.