CLLU1 expression and risk prediction in 175 patients with CLL. (A) Estimates of relative risk of early death as a continuous function of the CLLU1 mRNA expression level in CLL cells based on a Cox model. An expression level corresponding to that of normal B cells is denoted 1. Most observations are in the range between 0.5- to 1000-fold CLLU1 up-regulation, in which a proportional relationship between risk and CLLU1 fold up-regulation is indicated. The relationship was estimated to correspond to an increased risk of 7% for early death associated with each doubling of the CLLU1 expression level in this range. For CLLU1 expression levels less than 0.5-fold this relationship did not hold. (B) Overall survival according to low or high levels of CLLU1 expression used 40-fold up-regulation as cut-off. The median overall survival was 8.1 years for patients with low CLLU1 expression levels and 5.0 years for patients with high CLLU1 expression levels. (C) Time to first treatment according to low or high levels of CLLU1 expression. The median time to first treatment was 4.6 years in patients with low CLLU1 expression levels and only 9.0 months for patients with high CLLU1 expression levels.