While a comprehensive analysis of substrate specificity for each isoform is still missing, most features observed in LOXL1 knockout mice, including pelvic organ prolapse, enlarged pulmonary alveoli, and loose skin, all manifestations of defective elastic fiber formation, suggest that LOXL1 has a prominent role in elastin cross-linking [5,6]. Here, LOXL1 is linked to pelvic organ prolapse.