MMP-9 inhibition appears to attenuate memory consolidation (see our previous paper: (Bach et al 2018, Molecular Psychiatry). It could also be a target for blocking reconsolidation. In a new paper, we tested this hypothesis in human threat conditioning. We find that doxycycline has no specific impact on a reminded cue, but confers a global reduction in extinction learning and threat learning beyond the clearance of the drug. This may point towards a more long-lasting impact of doxycycline treatment on memory plasticity (Bach et al. 2019b, Journal of Neuroscience).