NOTCH1 and mantle cell lymphoma: A study by Kridel et al. identified 12% of MCL harboring Notch1 mutations, the majority consisting of a 2 base-pair deletion which truncates the C-terminal PEST domain, removing the recognition site for the FBXW7-SCF ubiquitin ligase degradation complex, resulting in a more stable and transcriptionally active form of Notch1-ICD [109].