BTK and sarcoma: Furthermore, the binding motifs of CRBN have emerged as highly valuable scaffolds for E3 ligase recruitment in several reported heterobifunctional degraders, including proteolysis targeting chimeras (PROTACs) currently under clinical study, such as ARV-471, ARV-110, and NX-2127 [13–15], as well as PROTACs targeting oncoprotein such as epidermal growth factor receptor (EGFR) [16], Kirsten rat sarcoma (KRAS) [17], c-mesenchymal-to-epithelial transition (c-MET) [18] and Bruton’s tyrosine kinase (BTK) [19] in preclinical studies.