There is a known causative link between the ubiquitin system and many human diseases including cancer, neurodegeneration, metabolic disorders and viral infections. Proteolysis mediated by the ubiquitin-proteasome system is regulated by different enzymes, which recently became an attractive target for drug discoveries. LifeSensors offers a number of inhibitors enabling researchers to decipher the function of Ub/Ubl isopeptidases and conjugating enzymes. Along with classical inhibitors of Ub/Ubl isopeptidases such as Ub-vinyl methyl ester and –vinyl sulfone, LifeSensors has a number of small molecule inhibitors. Our new addition includes inhibitors of Ub/Ubl conjugating enzymes. With an evergrowing interest in proteasomal activity that has been linked to cancer, inflammatory and autoimmune diseases, we now offer a collection of proteasome inhibitors. Several inhibitors including bortezomib are already used in the treatment of multiple myeloma. The most commonly used laboratory inhibitors, lactacystin and MG132 are now available in different quantities.