PLCG2 and B-cell chronic lymphocytic leukemia: Given that the read lengths of next generation sequencing are typically < 700 bp for short-read approaches [26], it is unclear from sequencing of genomic DNA fragments whether the above PLCG2 mutations, if identified in a single patient reside in a single PLCG2 copy, in two alleles from the same CLL cell, or in distinct genes from distinct cell clones.