MYC and Splenomegaly: Co-expression of BCL-XL or BCL-2 together with MYC resulted in splenomegaly in all animals with mean values for moribund animals at 757 mg for BCL-XL/MYC BALB/c (Figure 3E) and 899 mg for BCL-2/MYC BALB/c mice (Figure 3F).