TP53 and B-cell chronic lymphocytic leukemia: Together, this would suggest sequencing depths much >x4000 will be required to robustly identify all sub-clonal mutations, for example, patient 8 had a TP53 mutation (29%VAF) at TP2, detectable at TP1 in 9/15581 reads (0.1%VAF), equating to the presence of one mutant cell in ~1000 CLL B-cells.