The distributions of unrounded CCL3L1 copy number measurements plotted on a histogram from real-time QPCR and MLPA exon 3 assays. A. The real-time QPCR assay demonstrates substantial variation around integer values. Without defined gaps between each of the clusters, assignment of whole copy number is performed by rounding the data to the nearest integer. B. The MLPA assay demonstrates a distribution of 0–6 copies with peaks centered on integer values. Copy number assignment can be performed by the groups of samples to a particular cluster.