ROR1^PosCLL cells have enhanced survival, migration, and proliferation. (A) CLL-cell viability was assessed after 0, 3, 6, 24, or 48 hours and normalized to that of the cells at 0 hour (mean ± standard error of the mean [SEM]; n = 10 for each group). The initial absolute viability of all samples at 0 hour was of 81% ± 3% (mean ± SEM). Significant difference of the percentage live CLL cells between ROR1^Pos (n = 10) and ROR1^Neg (n = 10) subgroup is indicated by asterisks (Student t test; **P < .01). (B) Percentage of viability after 24 hours (left) and 48 hours (right) incubation. P values were determined by Wilcoxon matched paired nonparametric test. (C-E) After 3 hours of incubation, relative percentage of basal migration (C) and chemotaxis toward CXCL12 (D) or CCL19 (E) of ROR1^Neg or ROR1^Pos CLL cells, with or without Wnt5a (200 ng/mL), as indicated at the bottom of the graph. P values were determined by Wilcoxon matched paired nonparametric test. (F-H) CD154-induced proliferation of carboxyfluorescein diacetate succinimidyl ester (CFSE)-labeled ROR1^Neg (F) or ROR1^Pos (G) CLL cells (n = 3 per group) with (right) or without (left) exogenous Wnt5a in the presence of control IgG antibody or UC-961, as indicated in the upper left of each histogram. The results of assays on 1 representative CLL sample are shown with the percent of dividing cells. (H) The bars indicate the mean proportions of ROR1^Pos or ROR1^Neg CLL cells with diminished CFSE fluorescence from each of 3 different patients for each culture condition indicated at the bottom of the graph. Data are shown as mean ± SEM; **P < .01, *P < .05.