BRCA1 tumour suppression occurs via heterochromatin-mediated silencing.

Mutations in the tumour suppressor gene BRCA1 lead to breast and/or ovarian cancer. Here we show that loss of Brca1 in mice results in transcriptional de-repression of the tandemly repeated satellite DNA. Brca1 deficiency is accompanied by a reduction of condensed DNA regions in the genome and loss of ubiquitylation of histone H2A at satellite repeats.

Neprilysin-2 is an important β-amyloid degrading enzyme.

Proteases that degrade the amyloid-β peptide (Aβ) are important in protecting against Alzheimer's disease (AD), and understanding these proteases is critical to understanding AD pathology. Endopeptidases sensitive to inhibition by thiorphan and phosphoramidon are especially important, because these inhibitors induce dramatic Aβ accumulation (∼30- to 50-fold) and pathological deposition in rodents. The Aβ-degrading enzyme neprilysin (NEP) is the best known target of these inhibitors.