MMP9 and carcinoma of esophagus: Based on LCN2/LOXL2, LCN2/MMP9 and LOXL2/MMP9 protein–protein interactions, we further elucidated the molecular and cellular mechanisms underlying the LCN2/LOXL2/MMP9 ternary complex that promoted migration and invasion of oesophageal cancer cells, playing a synergistic role.