We found that patients with big ET-1 levels higher than a cutoff point of 5.4 pg/mL (established by ROC analysis) showed shorter time to first treatment (TTFT), as compared to CLL with low levels of big ET-1 (median TTFT, 58 vs. 129 months, p = 0.005, Figure 5C). Here, EDN1 is linked to B-cell chronic lymphocytic leukemia.