Part of this is the main determinant in the International Staging System (ISS), which predicts not only the prognosis but also the progression of asymptomatic disease (HR 3.30; P=0.002); despite this, it is important to take into account that renal insufficiency can elevate β2M levels and therefore complicates determination of the exact origin of an elevated serum level [11]. Here, B2M is linked to Renal insufficiency.