MMP9 and cancer: Hemopexin domain function depends upon disulphide bridging and disulphide bridging between the O-glycosylation or hemopexin domains facilitates gelatinase B/MMP-9 dimerization or oligomerisation, promoting CD44 binding, which results in activation of the EGF receptor and subsequent ERK/1/2 mediated cancer cell migration [46,48].