Hip (Hedgehog-interacting protein) is a type I transmembrane protein identified for its ability to bind biologically active Sonic Hedgehog.The hedgehog (HH) proteins are evolutionarily conserved protein, which are important morphogens for a wide range of developmental processes, including anteroposterior patterns of limbs and regulation of left-right asymmetry in embryonic development. Multiple cell-surface receptors are responsible for transducing and/or regulating HH signals. The Hip protein is a highly conserved, vertebrate-specific inhibitor of HH signaling. It interacts with all three HH family members, SHH, IHH and DHH. Two single nucleotide polymorphisms (SNPs) near this gene are significantly associated with risk of chronic obstructive pulmonary disease (COPD). A single nucleotide polymorphism in this gene is also strongly associated with human height.