NOTCH1 and B-cell chronic lymphocytic leukemia: Next-generation sequencing techniques have enabled detailed examination of the genome of CLL cells and have highlighted a number of high frequency genetic variants including NOTCH1, SF3B1 and BIRC3. Mutations of NOTCH1 have been associated with decreased levels of CD20 via a mechanism involving histone deacetylase-mediated repression of CD20 expression, resulting in reduced sensitivity to CD20-targeted therapies in vitro[23].