This gene encodes a precursor protein that belongs to the lysyl oxidase family of proteins. The secreted proprotein is proteolytically processed to an active mature peptide and a propeptide. This propeptide is thought to function in tumor suppression by inhibiting the Ras signaling pathway. The active enzyme plays a role in cross-linking of collagen and elastin and is essential for development of cardiovascular and respiratory systems, and development of skin and connective tissue. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Oct 2013]