The significance of sIgM levels and signaling for TTFT in CLL. The previous cutoffs of 50 (MFI) and 5% (iCa²⁺) were used to distinguish patients with high or low sIgM levels and signaling capacity, respectively.¹³  These cutoffs corresponded to the best cutoffs by receiver operating characteristic and Youden t tests when treatment was used as a state variable. (A) Patients with sIgM expression above (sIgM MFI high, dotted line) or below (sIgM MFI low, continuous line) the MFI cutoff of 50 were investigated for time to progression from diagnosis to requirement of treatment for the first time (TTFT). (B) Patients with sIgM signaling capacity above (sIgM high-signaler, dotted line) or below (sIgM low-signaler, continuous line) the cutoff of 5% were investigated for progression requiring treatment. Association between sIgM levels (C,E) and signaling capacity (D,F) with TTFT was also investigated in U-CLL and M-CLL, respectively. Survival analysis was performed by Kaplan-Meier algorithm.