BCL2L1 and B-cell chronic lymphocytic leukemia: As observed for NTSR1, the addition of NTS to B-CLL lymphocytes promoted sustained activation of NTSR2 and its downstream cascade, including phosphorylation of Src kinase (Figures 4a and b) and expression of the anti-apoptotic proteins Bcl-2 and Bcl-xL (Figures 4a and c).