This data set summarizes DNA copy number variation in 100 individual cancer cells harvested from a breast tumor. The cells belong to four subtypes, differing by ploidy.There are 47 Diploid+Pseudo-diploid, 24 Hypo-diploid, 4 Aneuploid B and 25 Aneuploid A cells. Their copy number profiles are summarized in terms of 354 amplification and deletion "cores", are computed by the CORE package.