MMP13 and atrial fibrillation: The downregulation of Col2 in injured samples is also consistent Pirvu et al,26 it was also documented as part of degenerative process without inducing an injury by Lang et al.47Very large and significant upregulation of MMP1, ADAMTS4 and a trend of upregulation of MMP13 in the AF of the repaired and injured samples at the injury site was not consistent with previous studies, where downregulation of catabolic genes was observed with diurnal loading.22, 26