B2M and Splenomegaly: In the multivariate analysis, the variables independently related to longer OS were the absence of splenomegaly (HR, 1.786; P = 0.023), low serum LDH (HR, 2.076; P = 0.018), low serum β2M (HR, 2.448; P = 0.006) and the presence of del(11q) in <40% of cells (HR, 3.145; 95% CI, 1.474–6.691; P = 0.003) (Table 3).