To assess whether the disease-specific occurrences of NOTCH-mutations were associated with differences in expression of either NOTCH1 or NOTCH2, we analyzed expression data of primary CLL (n = 54 cases) and MCL (n = 54 cases, 30 conventional MCL, and 24 non-nodal MCL)48. Here, NOTCH1 is linked to B-cell chronic lymphocytic leukemia.