The UPS pathway (ubiquitin proteasome system) is responsible for degradation of proteins in the cell. This pathway malfunctions in many cancer cells, therefore UPS inhibitors can constitute a new therapy used in i.a. cancer of the colon, prostate, lung, breast, in multiple myeloma, B-cell lymphomas, AML. The previously developed therapies, i.a. bortezomib – a proteasome inhibitor, are administered intravenously and are associated with significant adverse effects. Developing a safe, orally-administered inhibitor of protein degradation pathway will constitute a new treatment option for patients with both solid tumours and haematological cancers.