Copy number variation detection in chromosome 18 of an EBV-transformed sample. (a-d) CBS segmentation of chromosome 18 from the EBV-transformed single lymphoblastoid cell 1151 using global loess normalization (a), CGHnormaliter (b), poplowess (c), and channel clone normalization (d). The y-axis represents the log2 ratios and the x-axis represents the coordinates along the chromosome. The blue line represents the CBS segmentation line. The green region represents the duplication region called by the CGHcall program.