Fig. 1. Breakdown of TP53 aberrations detected in CLL based on the presence of TP53 mutations, their allele burden, and concomitant del(17p) as assessed by FISH.

Values were adopted from published studies employing ultra-deep NGS to detect TP53 mutations [4–10, 66]. High VAF—variants >10% VAF, low VAF—variants 1–10% VAF, except for two studies where variants <1% and >1% could not be distinguished [4, 5]. In patients with high VAF TP53 mutations, co-existence of del(17p) prevails. * In patients carrying low VAF TP53 mutation concomitant del(17p) is detected in only a minority of cases, but the true status is unknown due to the higher detection limit of FISH (>5% aberrant nuclei). The breakdown depicted here corresponds to pre-treatment cohorts (diagnosis or before frontline treatment). In the chemo-pretreated cohorts the proportion of patients with TP53 defects can reach 40% [1, 20, 106].