PRDM1 and cancer: Other examples of amplicon mosaicism include P5 (LumA) where an amplification targeting GATA6 was found only in a sub-population of cancer cells and P59 (Basal), where amplifications on multiple chromosomes (chromosomes 3, 5, 6 and 18) targeting important genes such as LOX (Cox et al., 2015) and PRDM1 (Nik-Zainal et al., 2016) where found in the majority of cells but absent in others (Figure 3—figure supplement 2A).