IL4 and B-cell neoplasm: The results of these experiments are also consistent with the observation that while IL-4 can act as a potent co-stimulus for proliferation survival and differentiation in both B and T lymphocytes, hence its widespread experimental use in generating B cell blasts, it also has a modest inhibitory effect on proliferation and induces apoptosis most notably in human B cell neoplasms, and in some non-hematopoietic malignant cells [3]–[10].