The human immune system serves as our body’s defense against harmful pathogens and cancer by identifying and eliminating abnormal cells. To maintain immune homeostasis several mechanisms are employed, which involve a wide range of proteins, including the Casitas B lymphoma-b (Cbl-b) protein, present in various immune cells. Cbl-b helps modulate immune responses by downregulating the activity of multiple immune cells. This inhibitory effect is significant in cancer development and progression as it promotes an immunosuppressive tumor environment.

While some kinases have been the focus of extensive drug discovery campaigns, others remain largely unexplored. These "understudied" kinases have received significantly less attention, leaving their functions poorly annotated in scientific literature. Cyclin-Dependent Kinase-Like 2 (CDKL2) is one such kinase, with no chemical probes previously developed to facilitate its study. This was set to change with a successful collaboration between Alison Axtman at SGC-UNC and the Bullock group at the Centre for Medicines Discovery at the University of Oxford.