In normal human fibroblasts or human tumor cells, expression of the phosphorylation mutants Bcl-xL(S49A) or (S49D), Bcl-xL(S62A) or (S62D), or dual Bcl-xL(S49/62A) or (S49/62D) has no significant effect on the apoptosis rate, but leads to mitotic defects associated with chromosome mis-attachement, lagging, bridging, mis-segregation, cytokinesis failure and aneuploidy [22, 23]. The gene discussed is BCL2L1; the disease is neoplasm.