GelA MMP-2 Clg4a Gene protein coding gene MGI:97009 genetic mapping 72kDa type IV collagenase gelatinase A matrix metallopeptidase 2 + http://identifiers.org/mgd/MGI:97009 72kDa gelatinase gelatinase A|MMP-2|GelA|Clg4a|72kDa gelatinase|72kDa type IV collagenase Mmp2 O