Clinical features of 20 spontaneous CLL regression cases. Spontaneous CLL regression cases were categorized into 4 groups: (A-K) complete spontaneous regression (red curves), (L-Q) partial spontaneous regression (blue curves), (R-S) spontaneous regression occurring prior to a second malignancy (green curves), and (T) relapsed spontaneous regression (purple curves). The ALC for each patient is plotted against the time elapsed from the date of diagnosis. Clinical features are annotated, and the time of peripheral blood sampling is displayed at the bottom each chart. T0 represents the diagnostic time point, whereas T1 and T2 represent the regression time points, except in CLL20 where T2 represents the relapse time point. LN, lymphadenopathy (the measurement displayed corresponds to the size of the largest palpable node); Tx, treatment.