CDR-deleted mice develop CD5⁺ B-cell expansions in the PB. Percentages of CD5⁺B220^lo cells among mononuclear cells of mice from CDR^fl/−CD19-Cre and CDR^fl/flCD19-Cre cohorts. P values (Wilcoxon rank-sum test) are indicated; the dotted line demarks the upper threshold for the normal range of CD5⁺B220^lo cells in a panel of 3- to 6-month-old wild-type mice determined by the average percentage ± 3σ; percentages above 4% are considered CD5⁺ lymphocytosis. Data are shown both as actual values (●) and as mean ± SD.